Low blood pressure

Also called Hypotension, Postural hypotension, Orthostatic hypotension

Usually harmless in a young person and a major cause of falls in an older one. The important measurement is standing up, and it is rarely taken.

What it is

Blood pressure lower than usual. In a fit young person it is often normal and needs no treatment at all.

It matters in two situations.

**Postural hypotension** is a fall in blood pressure on standing, causing dizziness, and it is a leading and eminently treatable cause of falls in older people. It is diagnosed by measuring lying and standing blood pressure, a simple test that takes a few minutes and is very often not done. Anybody who has fallen, or who feels dizzy on standing, should have it.

The usual causes are medicines, dehydration, and conditions affecting the autonomic nervous system such as Parkinson's disease, diabetes and multiple system atrophy. Medicines are the commonest and the most fixable: blood pressure tablets, diuretics, alpha blockers for the prostate, some antidepressants and antipsychotics.

**Acutely low blood pressure** in somebody unwell is a different matter entirely and can indicate sepsis, bleeding, a heart problem or severe dehydration. That is an emergency.

Blood pressure targets in frail older people are frequently too aggressive, and deprescribing is a legitimate and often overlooked intervention.

Signs you might notice

Dizziness or light-headedness, especially on standing up or after meals.

Blurred vision on standing, or a grey-out.

Fainting or near-fainting. See fainting.

Falls, sometimes without any remembered dizziness at all.

Fatigue, weakness, nausea, poor concentration.

999 or urgent: low blood pressure with confusion, cold clammy skin, very fast breathing, chest pain, black stools or vomiting blood, or in someone who is acutely unwell. That is shock and needs emergency assessment.

Urgent: fainting on exertion or while lying down, which points at the heart rather than at posture.

How it can affect day-to-day life

The postural drop is often worst first thing in the morning, after meals, in hot weather, after a hot bath, and after alcohol, and knowing that allows people to plan.

Compression stockings, adequate salt and fluid, and rising in stages are the practical measures, and they work.

Deprescribing is under-used. Reducing or stopping a blood pressure tablet in a frail person who is falling is often better medicine than adding a treatment for the low pressure.

For people who cannot report dizziness, dementia or communication differences, unexplained falls should prompt lying and standing measurements as a matter of routine.

Raising the head of the bed by a few inches genuinely helps overnight fluid distribution, and costs nothing.

Small frequent meals reduce the after-eating drop, which is a common and under-recognised cause of falls in care homes.

Supporting someone well

Ask for lying and standing blood pressure to be measured. This is the test, and it is regularly skipped.

Ask for a medication review, and be open to reducing blood pressure treatment in a frail person who is falling.

Rise in stages: sit up, wait, sit on the edge of the bed, wait, then stand holding something.

Increase fluid, and salt where that is safe.

Consider compression stockings, and raise the head of the bed a few inches.

Avoid large meals, alcohol and hot baths when symptoms are bad; eat smaller meals more often.

Treat any dizziness on standing in an older person as a falls risk, not a nuisance.

Get anyone acutely unwell with low blood pressure assessed urgently.

Where to get help

A GP practice or practice nurse for lying and standing measurements and a medication review.

999 for low blood pressure with confusion, chest pain, bleeding or acute illness.

A falls service for repeated falls.

Blood Pressure UK have clear information on postural hypotension.