Neurological red flags

A face that has fallen on one side, an arm that drifts down when both are raised, or speech that is slurred or muddled, coming on suddenly, are the classic signs of a stroke. Note the time the symptoms started, because it affects treatment, and call your local emergency number straight away.

A headache that arrives like a thunderclap and reaches its worst almost instantly, especially if it is the worst you have ever had, can signal bleeding around the brain. This is different from a bad headache that builds over hours. Treat it as an emergency.

New weakness or numbness down one side of the body or face, sudden loss or blurring of vision, or sudden severe dizziness with unsteadiness can all be signs of a stroke or another urgent problem, even if they seem to ease.

A first seizure, a seizure lasting more than five minutes, or one that repeats without the person recovering in between needs emergency help. Protect the person from injury, do not put anything in their mouth, and call for help.

After a knock to the head, seek emergency care for repeated vomiting, a worsening or very severe headache, drowsiness or confusion, a seizure, clear fluid or blood from the nose or ears, weakness, or a brief loss of consciousness. Anyone on blood thinners needs a lower threshold to be checked.

Back or leg pain together with new difficulty passing or controlling urine, numbness around the groin, buttocks or inner thighs, or weakness in both legs can be a cauda equina emergency. It is treated the same day to protect long-term function.

A headache that is genuinely new for you, that keeps getting worse over days to weeks, that is always in the same spot, or that starts for the first time later in life, is worth having assessed rather than assuming it is the usual kind.

Headache combined with a high temperature and a stiff neck, or with a rash that does not fade under gentle pressure, can point to an infection such as meningitis and should be acted on quickly.

Steadily progressing weakness or numbness in a limb, a foot that drags, worsening balance, or increasing clumsiness of the hands should be reviewed, particularly when it builds over days or weeks.

Pain travelling down an arm or leg along with numbness or weakness suggests a nerve is involved. Most settle, but persistent or worsening weakness deserves a review.

Back pain accompanied by fever, night sweats, unexplained weight loss, or occurring in someone with a past cancer, is worth prompt assessment to rule out less common causes.

Most back and neck pain improves within a few weeks. Pain that lingers beyond that, or that keeps returning, is worth reviewing to check the approach and rule out anything that needs a closer look.

Headaches that happen often, need regular painkillers, or interfere with work and sleep can usually be managed better once their pattern is understood, so they are worth raising.

Slowly developing changes in memory, word-finding or day-to-day functioning, particularly when family members notice them, are worth assessing. Many causes are treatable.

A dull, pressing headache across the forehead or both sides, without other symptoms, is most often a tension-type headache, the commonest kind. Occasional ones are usually managed with rest, fluids and simple measures.

Short-lived muscular back or neck pain, without the warning signs above, is extremely common and usually improves with gentle movement and time. Staying active generally helps more than bed rest.

Short-lived tingling in an arm or leg that has been in one position, which quickly resolves once you move, is a normal nerve response and not a cause for concern on its own.