Dysautonomia or Autonomic Dysfunction is a term used to describe a collection of symptoms that results from the autonomic nervous system not working quite right.
The consequence is an inappropriate pooling of blood volume (usually to the lower half of the body), inappropriate rapid drops and elevations in blood pressure, and inappropriate distribution of blood flow throughout the various organs of the body (too much to some and too little to others).
The most notable organ affected is the brain and momentary interruptions in the delivery of oxygen and nutrients to the brain leads to dizziness or lightheadedness, tunnel vision, black-out vision (complete loss of vision), hearing perception changes, and sometimes to loss of consciousness (fainting).
These most commonly occur when getting up from lying or sitting and this is known as orthostatic intolerance). Other common effects on the brain include foggy thinking, attention deficit, insomnia, mood disturbances and depression.
The body’s attempts at correcting the drops in blood pressure and derangements in blood flow often leads to the heart suddenly racing (palpitations) and the ebb and over-correction of blood flow to the brain is likely responsible for migraine headaches. Occipital headaches (back of the head) and neck pain (coat hanger’s pain) also occur.
The inappropriate distribution of blood flow often leads to poor flow to the arms and legs and this occasionally causes swelling of the feet or calves and often problems with temperature control of the body. The sensation of feeling very cold or uncomfortably hot when others are fine with the surrounding temperature is very common as is excessive sweating of the palms and soles. Other times, one loses the ability to sweat (anhydrosis). Sometimes the fingers and toes can become ice-cold and painful (Raynaud’s phenomenon) and skin sensation is altered creating tingling of the arms (paresthesias), tremulousness or shakiness, joint pains, and facial pain. Perhaps because the blood flow distribution and blood pressure throughout the body is not regulated well, the cardiovascular system constantly works very inefficiently causing great fatigue, generalized or leg weakness, and exercise intolerance. Indeed, autonomic dysfunction is though to be one important cause of chronic fatigue syndrome.
Because the autonomic nervous system also controls the gut, dysautonomia also often causes nausea, abdominal pain and digestion issues of various types. The urinary bladder is also innervated by this same system and so urinary frequency and incontinence sometimes occurs. The number and severity of these symptoms and how much they interfere with one’s life fall on a continuum from mild and occasional to debilitating and continual. When they interfere greatly with normal daily activity, the term POTS (Positional Orthostatic Tachycardia Syndrome) is often used.