Orthostatic (postural) hypotension: dizziness on standing in older adults

The BHF explains that when blood pressure drops, the heart rate normally increases and blood vessels elsewhere narrow to maintain pressure; if the heart rate does not rise enough, or vessels do not constrict enough, pressure falls. In postural hypotension this happens on standing. Guy's and St Thomas' lists lightheadedness or dizziness on standing, blurred eyesight, weakness, fainting, and feeling or being sick. The NHS adds confusion to symptoms of low blood pressure, which matters for older people whose dizziness or vague confusion may be put down to age.

The NHS says low blood pressure does not always cause symptoms and may be present in people who are fit and healthy; some people develop it as they get older. The BHF notes most people with low blood pressure do not notice symptoms and that blood pressure can also drop after eating, as more blood flows to the digestive system.

Guy's and St Thomas' lists dehydration, heart conditions that cause a slow heart rate or heart failure, hormone problems such as low thyroid levels or uncontrolled diabetes, and nervous system conditions such as Parkinson's disease. The BHF adds that medicines for Parkinson's disease and erectile dysfunction can raise the risk, and that medicines for high blood pressure, heart disease or depression, as well as some over-the-counter and herbal products, can cause low blood pressure. Blood loss, dehydration and severe injury can reduce blood volume, and in emergencies such as septic shock or anaphylaxis blood pressure can fall dangerously low.

Because many older people take several of these medicines, postural hypotension is often a medicines question as much as a heart one. The BHF notes that the target for blood pressure in people over 80 is slightly higher, because arteries stiffen with age; the NHS-based guide it quotes says ideally under 150/90mmHg (or 145/85mmHg at home) for those over 80.

Guy's and St Thomas' says a GP can diagnose it with simple tests: measuring blood pressure lying down and standing up, and blood tests for thyroid and sugar levels. Further tests may include an ECG and a tilt table test, where you lie on a couch that slowly tilts up and down while blood pressure and heart rate are monitored.

The NHS says you can have your blood pressure checked by a pharmacist, practice nurse or GP, or at home with a monitor, and suggests seeing a GP if you keep getting symptoms such as dizziness and fainting. Keeping a short diary of when dizziness happens, what you were doing, and any new medicines helps the doctor.

Guy's and St Thomas' suggests drinking more fluids but less caffeine, reviewing medicines (a GP can change blood pressure medicines that increase the problem), and taking time to stand up: sit down again if dizzy and make sure the lightheadedness has gone before walking. A medicine called fludrocortisone can increase blood pressure and reduce the effects; if it is used, the GP needs to monitor closely to make sure it does not cause high blood pressure. The BHF describes fludrocortisone as a steroid that makes the kidneys retain water and salt, increasing blood volume.

The NHS adds getting up slowly from sitting to standing, taking care when getting out of bed by moving slowly from lying to sitting to standing, eating small frequent meals and lying down or sitting still for a while after eating, and drinking more water. It advises avoiding standing or sitting for long periods, bending down or changing posture suddenly, and drinking too much alcohol. Support stockings can improve circulation and raise blood pressure, per the NHS, though the BHF advises asking a doctor whether they are suitable. The BHF also lists drinking more fluids (check first if on a fluid restriction) and raising the legs. The NHS says medicine to increase blood pressure is rarely needed because simple measures or treating the cause usually work.

Guy's and St Thomas' directs people with postural hypotension to falls-prevention information. Practical steps include sitting on the edge of the bed before standing, having a stable support nearby, keeping a bedside drink, and reporting any faint or fall to the GP. The NHS says a GP appointment is appropriate if symptoms such as dizziness and fainting keep happening; for a faint with chest pain, palpitations, injury or incomplete recovery, call 999 as described in the fainting guidance.