Low blood pressure
Blood pressure that is lower than usual. For many people it is normal and healthy, but if it causes dizziness, faintness or fatigue — or drops on standing — it can point to dehydration, medications, or a hormonal cause such as adrenal insufficiency worth checking.
What it means
Low blood pressure (hypotension) means the pressure in the arteries is lower than usual. On its own this is often not a problem — many fit, healthy people, especially the young, run a naturally low blood pressure and feel perfectly well. It becomes relevant when it causes symptoms, or when it drops noticeably. A common pattern is a fall in pressure on standing up (postural or orthostatic hypotension), causing light-headedness or faintness, often due to dehydration, blood pressure medications, or ageing. Other causes include blood loss, heart problems, infection (sepsis lowers pressure), and — importantly for hormone testing — adrenal insufficiency, where a lack of the hormones cortisol and aldosterone causes low blood pressure, salt craving, fatigue and sometimes dangerous drops during illness. Pituitary underactivity (hypopituitarism) can do the same by reducing the adrenal drive. So while low blood pressure is frequently benign, when it comes with dizziness, fainting, marked fatigue, or symptoms of a hormonal or heart problem, it deserves assessment.
Common causes
- A naturally low blood pressure — common in fit, healthy people; not a problem.
- Dehydration — from poor intake, heat, vomiting or diarrhoea.
- Medications — blood pressure drugs, diuretics, some others.
- Standing up (postural hypotension) — a fall in pressure on standing.
- Adrenal insufficiency — low cortisol and aldosterone; with salt craving and fatigue.
- Hypopituitarism — reduced adrenal drive.
- Blood loss, heart problems, or infection (sepsis) — with acute illness.
Lab work-up approach
Low blood pressure is first assessed clinically — measuring it lying and standing, reviewing medications, and looking for dehydration or blood loss. Blood tests help when a cause like adrenal insufficiency is suspected: cortisol (often a morning level, sometimes with a stimulation test), sodium and potassium (a low sodium with high potassium is a clue to adrenal failure), ACTH, and kidney function. A full blood count checks for anaemia or blood loss, and markers of infection are checked if sepsis is a concern. Mediora.AI can surface a low-cortisol, low-sodium pattern that points toward an adrenal or pituitary cause, but low blood pressure with fainting, marked fatigue or acute illness needs prompt clinical assessment by your doctor.
Tests Mediora.AI can interpret
Related conditions
Panels to consider
When to see a doctor
A naturally low blood pressure with no symptoms usually needs no action. See a doctor if low blood pressure causes recurring dizziness, faintness or falls, or comes with marked fatigue, salt craving, weight loss or darkening of the skin — a combination that can point to adrenal insufficiency, which is very treatable but can become dangerous during illness. Review any medication that may be responsible. Seek urgent care for low blood pressure with severe symptoms — fainting, confusion, chest pain, breathlessness, or signs of infection — or if someone with known adrenal insufficiency becomes unwell (a risk of adrenal crisis). Mediora.AI helps flag the cortisol, sodium and adrenal markers; symptomatic or unexplained low blood pressure is assessed by your doctor.