Like many people with a chronic illness, I often found myself asking God (or my mom, who is a goddess in her own right), "Why is this happening to me?" My mom is always able to come up with a nice thing to say, which usually makes me feel better. God hasn't answered me directly yet, and I may never find out exactly why I came down with POTS. I like to think that I was chosen to have this crummy illness because I am a natural advocate (an attorney by profession), and it sure seems like people with POTS need more advocates in this world, since the illness is not well known amongst the general public and even by the medical community. Or I could just have really bad luck...
Whatever the reason was for me getting POTS, I may never know. However, in a practical sense I have been able to identify some of the underlying physiological mechanisms that are causing my various symptoms. I strongly believe that the more you know about your body and your illness, the better prepared you will be to fight it. It's also important to know what's going on with your body, because not many doctors understand POTS. Your regular family doctor may have never heard of it. Even neurologists or other specialists you visit may have one or two other patients that have had it, but chances are they don't have a detailed knowledge of it. It's a very challenging disorder that can effect almost every system in your body. Here's what I have learned about what's probably causing my various symptoms. I say "probably" because I want you to be clear that I am not a doctor, this is not medical advice, and what I say here may not explain what is causing you're symptoms. Here goes...
Low Aldosterone/Low Blood Volume
Through specialized endocrine blood tests we discovered that I have very low levels of the aldosterone, an essential life sustaining hormone produced by your adrenal glands that controls the balance between sodium and potassium in your body, which allows your body to absorb and excrete the proper amount of water each day. Without aldosterone, you can go into an adrenal crisis - your body will become so dehydrated, you can go into shock or, in extreme cases, you can die. Many people with POTS have low aldosterone, although we have not been able to identify a particular cause of my low aldosterone yet. There are lots of different things that can cause low aldosterone (high sodium diets, laying down too much, autoimmune diseases, infections, etc.), but some people have low aldosterone for an unknown reason (called idiopathic hypoaldosteronism). Low aldosterone causes your body to excrete too much water and sodium, and causes you to have high levels of potassium in your blood. Without enough aldosterone, your body cannot retain the water and sodium from the foods and beverages you consume, which leads to dehydration. Without enough water in your body, you develop low blood volume. Many of the troubling symptoms of POTS are the result of low blood volume, which doctors call hypovolemia. Studies have shown that some POTS patients are missing one third of the normal blood volume expected for someone of their size.
Low Blood Pressure Triggered By Low Blood Volume
Low blood volume causes low blood pressure. Since there is not enough blood in your body to push against the walls of your blood vessels, veins and arteries, your overall blood pressure is lower than it should be. 120/80 is usually considered the "ideal" blood pressure for adults, but many people have healthy blood pressure that is slightly lower than this. When I was at my worst with POTS, before any medication to replace my missing aldosterone, my laying down (supine) blood pressure was as low as 80/40 and I could not stand up without passing out, because standing up would have lowered my blood pressure even lower than that.
When a healthy person stands or sits up, the blood vessels in the lower parts of their body are sent messages from various parts of their nervous system telling the vessels to constrict, which pushes the blood upwards and counters the effect of gravity. This ensures that blood will reach your upper body and brain even when you're standing up. When someone with low blood volume stands up, even if the messages are sent to the blood vessels in their lower legs, and even if the vessels constrict, there may not be enough blood in their body to supply sufficient amounts of blood to their upper body and brain when they stand or sit up.
The low blood pressure and low blood volume contribute to a lack of blood flow to the upper body and brain - this causes many of the symptoms of POTS. Sometimes doctors use the term cerebral hypoperfusion, which means not enough blood is getting to the brain. For me, cerebral hypoperfusion seems to cause my headaches/stabbing/shooting head pains, difficulty concentrating/forgetfulness, brain fog, cognitive impairment and not being able to recall the word I am trying to say. This is usually relieved after I lay down for awhile.
Tachycardia(Racing Heart Beat)
The blood flow in the human body is run by a very complex system of checks and balances, and I do not claim to fully understand it (yet!), but I do know that when receptors in your neck, called barorecptors, sense that there is not enough blood flowing to your brain, they send messages that result in your heart beating faster, which is your body's attempt to get more blood to your brain. In a healthy person, your heart would be faster for a few moments when you stand up, your blood vessels in your lower body will constrict, pushing your blood upwards against the force of gravity, and you're baroreceptors in your neck would sense that you're brain is now getting sufficient blood supply, so that your heartbeat would return to normal. But in someone with low blood volume, you heart will be faster, but there still won't be enough blood to get to your brain when you stand up, so you're baroreceptors tell your heart to be faster and faster, and you're heart will do that in an effort to make sure you're brain is protected from damage due to low oxygen levels - similar to an 'ischemic stroke.'
My heartbeat will be a pretty normal 60-80 bpm when I'm laying down, and by simply standing up, within seconds my heartbeat starts racing up and up to over 130. The highest recorded measurement I had, before I was on medication, was 230 beats per minute, which is very dangerous, especially if it goes on for too long. I collapsed to the floor shortly after this reading was taken, probably because my brain was trying to protect itself by making me pass out, which helps return proper blood flow to the brain.
Passing Out/Almost Passing Out
When you're heart beating faster and harder isn't enough to compensate for the lack of blood flow to your brain, thankfully, you're brain is smart enough to protect itself from a lack of oxygen, so it makes you pass out, which usually results in you laying flat on the floor, in order to get that blood flowing back to your brain. In that sense, passing out is almost a good thing - it's better to pass out for a few minutes than to suffer with a lifetime of brain injury that was caused by a lack of oxygen to your brain (an ischemic stroke)! That's why it's so important for people with POTS to let friends and family around them know that if they feel very lightheaded or like they are about to pass out, the best thing to do is lay down with your feet slightly elevated. Sometimes people try to help someone who is dizzy by holding them up or preventing them from falling out of a chair. While it is certainly polite of them to help, it would be better to safely lay the person's head on the ground and slightly elevate their feet and legs. Hitting your head on furniture or a hard floor is probably the most dangerous part of passing out with POTS, so try to pass out gracefully if you can. :)
I'm "lucky" to get pre-syncope symptoms, that is, my body gives me warning signs a few seconds before I pass out. I get lightheaded, dizzy, off balance feeling, my vision gets grayed out or blurry or tunnel vision, I feel like my blood is being flushed downwards to my feet, my legs feel heavy, like I'm wearing cement shoes, and I usually get a bit sweaty on my upper body, I feel shaky and I feel short of breath. Just a few seconds of feeling like that is enough for me to know I have to lay down ASAP, to avoid passing out and hitting my head. Unfortunately, some people with POTS and other syncope disorders do not get any warning signals, and they can be in the middle of doing something and all of a sudden they fall over like a marble statute. If you see this happen, don't lift their head up. Wait a few seconds to see if they "wake up" or call 911 - especially if they hit their head hard or they don't wake up quickly. If you are "lucky" enough to get pre-syncope warning signals, there are a few counter maneuvers or body positions you can try to help increase blood pressure and blood flow to your brain. I will be posting information on these counter maneuvers in a future posting called "Coping With POTS."
One of the chemical messengers your brain uses to tell you're heart to beat faster is adrenaline (also called epinephrine). Adrenaline is very good at doing its job and when it is released into your bloodstream, you're heart will be faster and harder, which is you're bodies way of trying to get more blood to your brain, to protect your brain from injury due to low oxygen. Adrenaline is the chemical that causes that rush you feel when you get really scared by something - it causes an instinctive "fight or flight" response. Lots of adrenaline flowing through you body can make you feel shaky, anxious and very uncomfortable. Doctors sometimes use the word tremulousness to refer to this shaky feeling. Too much adrenaline can also cause you to get the chills or to get overheated very easily. Adrenaline can also make your senses feel like they are on overdrive and can cause over-stimulation.
When I lay or sit still, I can almost always feeling my pulse in my neck, eyes, head, stomach and pretty much everywhere else. When my heart is pounding very fast, I can also see my pulse flashing in my eyes. These are annoying symptoms, probably caused by a mix of the tachycardia, over stimulation and oversensitivity of your nervous system, and the anxiety like symptoms caused by the adrenaline surges people with POTS get.
While most people with POTS experience these adrenaline induced symptoms that can look or feel like an almost permanent panic attack, not everyone with POTS has 'true' anxiety or panic disorder. Studies have shown that about 97% patients with POTS were first misdiagnosed as having anxiety or panic disorder, when in fact they really had a disregulation of their autonomic nervous system. That's not to say that people with POTS can't have 'true' anxiety or panic disorder. After all, half a million people in the US have been diagnosed with POTS. Certainly out of a population that large there are going to be a percentage of people that have 'true' anxiety or panic disorder in addition to their POTS diagnosis. I was misdiagnosed with about 30 different conditions before we found out I had POTS, with several doctors telling me it was "all in my head" and I should just calm down and take a Valium. Ironically, the only doctor who assured me that it was definitely not in my head and that I had a 'real' medical condition and definitely not anxiety or panic disorder was a psychiatrist! I'm going to write about my misdiagnosis nightmare in another post, "POTS-Misdiagnosis Nightmare."
If you think you have POTS and you're doctor is telling you it's all in your head - find a new doctor ASAP - and don't stop looking until you find a doctor who takes your seriously and will run the proper tests on you to diagnose or rule out POTS. Check out my POTS Resource Links at the bottom of this page to see a list of doctors and medical centers that can diagnose and treat POTS.
Chest Pains/Tingling Extremities/Tinnitus/Visual Disturbances
The low blood flow to the upper part of your body doesn't just effect your brain and heart. Low blood flow to my arms causes a cold, tingling and pins and needles feeling in your hands and arms. Low blood flow to you chest, lungs and heart can cause shortness of breath (called dyspnea) and chest pains. Low blood flow to your head can cause ringing in your ears (called tinnitus), and visual disturbances.
POTS is not just about low blood flow. Many people with POTS have some dysfunction of their autonomic nervous system. Your autonomic nervous system controls your breathing, your heart beat, your blood vessels, your blood pressure, digestion, urination, etc. Basically, it controls all of those things your body does for you that your don't have to think about. For example, when you eat a cheeseburger, you don't have to tell your stomach to digest that cheeseburger for you. Your autonomic nervous system controls the various parts of your digestive tract and takes care of that cheeseburger while you get to do something more interesting.
Dysautonomia can involve damage to the autonomic nerves themselves, or a problem with the chemicals that send messages between the nerves, called neurotransmitters.
Peripheral Small Fiber Neuropathy
My low blood pressure is also partially caused by the fact that the nerves that control the constriction of the blood vessels in the lower parts of my body are damaged. This damage to these nerves is part of my dysautonomia. I had a 3 mm punch hole skin biopsy (without anesthetic because I was allergic to the anesthetic shot the had available-OUCH!), when my doctors were looking for mastocytosis, another disease that can cause POTS like symptoms. The lab results showed that I did not have mastocytosis, but that my small fiber nerves at the location of my biopsy (my left calf) were 80% deficient - 60% of the fibers that should have been there were completely missing (as a result of nerve death) and 20% of the fibers were still present, but showed signs of damage. That leaves 20% of nerve fibers that were "normal." Doctors have various terms for my dead and damaged nerve problem - Peripheral Small Fiber Neuropathy, Autonomic Neuropathy, Peripheral Autonomic Neuropathy. Neuropathy is a term doctors use to describe when nerves have been damaged or have died off. The name is less important that to understand which nerves are involved, and which of my body systems will be effected by this nerve death/damage.
Roughly speaking, there are two areas of your nervous system: the central nervous system (CNS) which includes your brain, brain stem and your spinal cord, and the peripheral nervous system, which controls the nerves that flow from your spinal cord to the various organs and other parts of your body. Then there are three important types of nerves that can be involved in "peripheral" neuropathy - sensory nerves (that control pain, touch, pressure, hot/cold sensations), motor nerves (that control your ability to relax/contract your muscles, movement, walking, etc.) and autonomic nerves (that control your involuntary body functions such as breathing, digestion, blood pressure, heart beat, etc.). In your legs, if you lose autonomic nerves, it impairs the constriction of your blood vessels, and makes it more likely that blood will pool in your legs when you sit or stand upright, causing low blood pressure and all of the symptoms resulting from low blood pressure.
All three types of peripheral neuropathy (autonomic, motor and sensory) generally (but not always) start at the farthest points of the nervous system from the brain. For example, people who have sensory peripheral neuropathy tend to notice numbness, tingling or pain in their toes first, and then if their peripheral neuropathy continues to spread, it can start to move up higher up their leg to their knees. Sometimes it also starts in their fingers and spreads up their arms too. While I've only had one skin biopsy, which is the best way to identify autonomic small fiber peripheral neuropathy, I suspect that my autonomic neuropathy has spread up to my mid-thigh region and that it is in my hands as well. Signs indicating to me that my peripheral nerves are damaged in my legs and arms include tingling, pain, numbness, coldness, lack of sweating or too much sweating, blotchy purple skin color and swelling in my lower arms and legs when I stand up, the veins on the top of my hands tend to fill up with blood and get swollen when I put my hands below my heart level, and then they flatten out and my hands get almost immediately cold and clammy when I raise my hands above my heart level.
I am awaiting further testing to better delineate and describe the location and specific type of neuropathy I have, and I'm also trying find out what caused my neuropathy. Hopefully it is something temporary (like an infection) that is not causing continuous damage to my nerves. There is hope for people with peripheral neuropathy - under ideal conditions, your peripheral nerves can grow back healthy about 1mm per year. Small fiber nerves, the kind I know are damaged in my legs, are very tiny, so 1mm of growth is a huge amount of healing to be happening in one year. This is why it's so important to get a baseline level on how severe you're neuropathy is when it's first discovered - then you can go back a year or two later and see if you're nerves have grown back, stayed the same, or if they have gotten worse.
Acid Reflux/Vomiting/Diarrhea/Stomach Pains
When something is wrong with your autonomic nervous system, it's as if there is a short circuit in one or more places in your body and things that were supposed to happen on their own start to not work as they should. I developed acid reflux for the first time in my life when I developed POTS. This is likely because the peripheral nerves that control my lower esophageal sphincter - the valve at the bottom of your esophagus that keeps stomach acid down in your stomach - isn't working properly. Sometimes my valve stays open, probably because the nerves that once told it to stay shut are damaged. This valve is probably also "leaky" because my diaphragm muscle, the muscle under your lungs that control your breathing, is also weakened - possibly due to autonomic nerve damage or due to a problem with the muscle strength itself (I don't know yet-more tests I need to have). We do know, as a result of pulmonary function tests that my ability to breathe in and out really hard and fast is about 70% weaker than it should be.
There are also nerves that control how quickly something passes from your stomach to your intestines, and how quickly something travels through your intestines to... well you know.. the toilet. OK... if you don't want to hear about this, skip to the next paragraph. While I don't want to gross out anyone reading this, especially those of you who know me, I think it's important to share this information with other POTS patients so they know they are not alone in suffering, and so that maybe someone else suffering with these symptoms will go to their doctor with this info and get an accurate diagnosis. So grow up... everyone poops! I had horrible diarrhea when I first came down with POTS - several times a day for several months, usually starting when I woke up in the morning and lasting until about 3 pm. At the same time this was happening, I was puking once or twice a day for about the first three months. Of course that caused me to lose about 50 pounds within the first few months I was sick. I became malnourished and dehydrated, even though I was eating a very healthy, but high calorie diet, and I was drinking 2 liters of water and electrolyte fluids (PediaLyte and Coconut Water) a day. Thank goodness I was a little chunky when I first got sick. I went from 180 lbs. to 130 lbs. in three months. I'm 6 ft tall and I was very athletic, so even though 180 sounds like a lot, I didn't really look that heavy at 180 (but that was the heaviest I ever was in my life), and I looked emaciated at 130. The last time I weighed 130 lbs. was junior year of high school and I don't think I was as tall back then.
Thankfully my bowels are doing a little better now, but my GI symptoms still act up one in a while, and we're not really sure what triggers it, but I have some educated guesses (more on that later). I'm back to a healthier looking 148 lbs. and I really have to work at it to keep my weight up (mostly I'm worried that losing weight means I'm not absorbing the vitamins and minerals I need to get healthy). I get a bloated/full feeling even from eating small meals, I get stomach aches if I drink too much water at once, I vomit about once a week - usually right after drinking fluids - we're not certain, but it is probably because the autonomic nerves that control the speed of my digestion or my stomach valves are damaged. This is unpleasant, but it could have been worse - some people with autonomic nerve damage cannot control their bladder or their bowels at all. I consider myself lucky that those parts are still working for me.
Your autonomic nervous system also plays a big role in regulating your body's temperature. It's likely that the chills, goosebumps, overheating and night sweats I get are because of damage to some of the nerves in my autonomic nervous system, although these body temperature related problems can be exacerbated by too much adrenaline, which is discussed above.
Shortness of Breath/Hyperventilation/Sore Neck and Shoulders
Many people with POTS, myself included, have persistent shortness of breath. In my case, it seems to be worse when my other symptoms are worse, it's worse in the morning, in the cold and it also seems to be worse when I stand or sit up. Many POTS related problems can contribute to shortness of breath, and in my case I honestly don't know what's causing it, but I suspect it has something to do with the low blood flow to the upper part of my body. If my heart or lungs aren't getting enough blood, I end up gasping for air, feeling oxygen starved. It could also be caused by damage that may have occurred to my peripheral autonomic nerves in my controlling my heart/lungs/diaphragm - my doctors are looking into that, but figuring out your POTS symptoms is a long process.
When I feel short of breath, sometimes I start to hyperventilate. Many people associate hyperventilation with anxiety, and just think "if you calm down, you won't hyperventilate." In some cases, I'm sure that's true, but my hyperventilation only happens when my other symptoms are bad or when I've been standing upright too long and my pulse starts to race, so I think it is more of a biological trigger than an emotional one. Let me be clear - it is pretty terrifying when you feel like you can't breathe and your heart starts racing to 130+. Even the calmest person in the world would get a little rattled if that was happening to them several times a day without explanation! I'm sure the surges of adrenaline (explained above) and the racing/pounding heart beat don't help the breathing situation either. But personally, I don't think my hyperventilation has much to do with emotional or anxiety triggers. I was on vacation in VT snowboarding and having the time of my life (totally relaxed!) when the first hyperventilation attack happened to me, and happened about an hour after I had my first horrendous attack of diarrhea and vomiting (at a ski lodge of all places).
Hyperventilation can also be a sign of an acid-base imbalance. When you hyperventilate, you blow out too much carbon dioxide, which your body needs to maintain the pH balance of your blood. When you hyperventilate, your blood may be fully oxygenated, but the abnormal pH of your blood makes it difficult for that oxygen to reach the tissues that need it - essentially causing a low oxygen condition even though your blood is filled wit oxygen. Many different medical conditions and medications can cause a problem with the pH balance in your body, including low aldosterone and some drugs used to treat low aldosterone. I'm awaiting tests from my doctors to see an acid-base disorder this may be triggering my hyperventilation.
All of this gasping for breath usually results in me breathing shallow breaths from my upper chest area, rather than using my diaphragm to breathe deeply. This may be the way I breathe because my diaphragm is damaged, as explained above, but it's also natural to breathe quick shallow breaths when you hyperventilate or have other breathing difficulties. Repeated shallow upper chest breathing can put a strain on chest, neck and shoulder muscles, and that is probably why they get so sore sometimes. Also, since people with POTS tend to lay down so much, they may be developing bad posture or may be weak from inactivity. I am definitely guilty of this. When I was in the hospital for two months, I could barely hold up the weight of my own head because my neck and back muscles had become so weak. That started because when I was first admitted to the hospital, they wouldn't let me out of bed AT ALL because they didn't know why my heart was racing so high every time I stood up. It was really degrading - they made me use a bedpan to go to the bathroom. I was not happy about that and I didn't think it was necessary. Sometimes if the nurse wasn't around, I sneak over to use the bathroom, holding on to my IV pole for balance - within seconds the nurses would come running in to my room screaming at me because my heart monitor alarm would start beeping because my heart was racing off the charts. Of course, all of that forced bed rest only made all of my symptoms worse. I eventually convinced them to give me one of those little portable potties, so I could retain a tiny fraction of my dignity!
I am extremely tired all the time since I developed POTS - just washing dishes for a few seconds or walking from my bed to the bathroom makes me exhausted. When you heart beats so fast just from sitting or standing up, naturally - you get tired really quickly. It feels like I've just completed a hour long cardio work out, without that energizing feel good sensation you get after a real workout. Also, lots of people with POTS report feeling very tired after a passing out episode. I don't notice this, but I think it's because I'm just tired all the time anyway.
It can be hard for me to sleep. It's pretty difficult to fall asleep with your pulse racing and your head spinning with dizziness and your pulse flashing in your eyes, and thumping in your neck and temples, and don't forget the stomach aches and acid reflux creeping up into your throat. I have to fall asleep with the TV on and the volume turned up pretty loud. That way I can't hear my pulse and I can't see it in my eyes because the ambient light and flashing from the TV masks it.
Speaking of fatigue, I don't have the energy to type anymore right now. I'll be back with another post when I'm feeling a little better...