Orthostatic intolerance is a term that is sometimes used to describe symptoms of PoTS. It means symptoms that occur on standing and are relieved by lying down. In addition to heart rate and blood pressure, other bodily functions that are regulated by the autonomic nervous system can be affected. Symptoms can fluctuate from day to day and include:
Dizziness or light-headedness or presyncope (almost fainting)
- These symptoms usually occur when standing up, but can occur with prolonged sitting.
Syncope (fainting or blackouts) - Approximately 30 % of people with PoTS experience syncope.
Tiredness or weakness - These are common symptoms of PoTS and can last for a considerable time after a bout of symptoms of PoTS.
Brain fog - People with PoTS often complain of ‘brain fog’ which is difficulty in thinking or concentrating.
Palpitations are a sensation of your heart pounding in your chest.
Shortness of breath - Patients can feel breathless when standing up or with slight exertion.
Excessive or reduced sweating
Gut problems - Nausea is common. Other symptoms include diarrhoea, constipation, bloating, abdominal pain and vomiting. Many people with PoTS are told that they have irritable bowel syndrome.
Headaches - These can be orthostatic headaches which means they occur as a result of being upright and may be caused by reduced blood supply to the brain. People with PoTS also commonly experience migraines and migraine-like headaches which are worse when the patient is upright.
Visual problems - This can be described as excessive glare, blurred or tunnel vision.
- Excess heat
- After eating - especially refined carbohydrate eg sugar, white flour
- Speed of positional change - don’t stand up quickly
- Time of day (may be worse in the morning, especially rising after wakening)
- Menstrual period
- Deconditioning or prolonged bed rest
- Alcohol which dilates blood vessels
PoTS symptoms can be:
- Severe - with marked limitations of daily activities
Written by: PoTS UK Team
Medically approved by: Dr John Purvis and Dr Satish Raj
Review date: 1/12/14