Subdural haematoma

Also called Subdural haemorrhage, Bleed on the brain

A slow bleed that can appear weeks after a knock nobody remembers. In an older person it looks exactly like dementia, and it is reversible.

What it is

A collection of blood between the brain and its outer covering.

The acute form follows major head injury and is an immediate emergency. The chronic form is the one this entry is really about, and it is one of the most important reversible diagnoses in older people's health.

A chronic subdural develops over weeks. The trigger can be a minor head knock the person does not recall, or no remembered injury at all. Risk rises with age, because the brain shrinks slightly and the bridging veins are stretched; with alcohol; and above all with anticoagulant and antiplatelet medication.

It matters because of what it imitates. Gradual confusion, drowsiness, unsteadiness and personality change in an older person get diagnosed as dementia or written off as ageing. A CT scan takes minutes, and surgical drainage frequently returns the person to how they were. Missing it means someone is placed in long-term care for something curable.

Any older person with a new or unusually fast cognitive decline, particularly on anticoagulants or after a fall, deserves a scan.

Signs you might notice

Acute, after significant head injury: worsening headache, vomiting, drowsiness, confusion, weakness on one side, seizure, unequal pupils. This is 999.

Chronic, over weeks: headache that comes and goes; increasing confusion or memory problems; drowsiness and sleeping more; personality or behaviour change; unsteadiness and falls; weakness on one side; difficulty speaking; and sometimes new incontinence.

Fluctuation is characteristic. Better one day and worse the next is a clue, and it is one that distinguishes this from most dementias.

Urgent same-day assessment for cognitive decline over weeks in anybody older, particularly on blood thinners, with any history of falls or head knocks.

How it can affect day-to-day life

The most common route to a missed diagnosis is that nobody mentions the fall. A knock on the head three weeks ago does not feel connected to being muddled today, so it never gets said.

Care records help enormously here: an accurate falls log means the connection can be made by somebody reading back.

Anticoagulation raises the risk, but stopping it has its own risks, and the decision after a bleed is specialist. Never stop or restart without advice.

Recovery after drainage is usually good and can be dramatic. It is also not always complete, particularly in the very frail, and recurrence happens in a minority.

Anybody on anticoagulants who bangs their head should be assessed the same day, even if they feel fine.

Supporting someone well

Record every fall and every head knock, with the date. That record is what makes the diagnosis.

For any older person who becomes confused, drowsy or unsteady over weeks, ask directly for a CT head scan and say subdural.

Treat a head injury in anybody on anticoagulants or antiplatelets as urgent, on the day, whatever they say about feeling fine.

Watch for fluctuation and report it; it is a strong clue.

Do not accept a rapid decline as dementia. Dementia is slow; weeks is not dementia.

After surgery, expect a gradual recovery and watch for symptoms returning, which can mean recurrence.

Address the falls themselves; the bleed is a symptom of falling. See falls.

Where to get help

999 after significant head injury or for rapid deterioration.

A GP practice or NHS 111 the same day for gradual confusion, drowsiness or unsteadiness in an older person.

Headway on 0808 800 2244.

Brain and Spine Foundation for information on recovery.