Family history of multiple sclerosis: what raises the risk?

The NHS describes multiple sclerosis as a condition that affects the brain and spinal cord. It cannot currently be cured, but treatment can often help manage it. NHS inform explains that in MS the immune system attacks the protective myelin sheath around nerves, making it inflamed in small patches, and says it is a lifelong condition that can sometimes cause serious disability.

The NHS says MS is different for everyone, with symptoms that can come and go as relapses and remissions, and may get worse over time. Most people with MS live into old age, although the NHS says life expectancy is on average a few years less than the general population.

The NHS lists having a brother, sister or parent who has MS among the factors that might make you more likely to develop it. NHS inform explains it more precisely: MS is not directly inherited, but if you are related to someone with the condition, you are more likely to develop it.

The same NHS inform page says MS is likely to be partly caused by genes you inherit from your parents and partly by outside factors that may trigger the condition. It adds that MS is not caused by anything you have done, and it is not clear whether you can prevent it.

The sources used here do not give a percentage risk for relatives, and the figure will vary with how many relatives are affected. A neurologist can discuss your situation, and it is reasonable to ask your GP if you are concerned.

Family history is only one of the risk factors the NHS names for MS. Some of the others are things you cannot change and one is under your control.

• Age: you might be more likely to get MS if you are aged 20 to 50.

• Sex: women are more likely than men to get MS.

• Smoking: people who smoke are about twice as likely to develop MS.

• Viral infection: having had the Epstein-Barr virus, which causes glandular fever, may trigger the immune system in some people.

The NHS says there are many possible symptoms and everyone with MS is affected differently. Common symptoms include feeling extremely tired, problems with your eyes or vision such as blurred vision or eye pain, numbness or tingling in different parts of the body, feeling off balance, dizzy or clumsy, muscle cramps, spasms and stiffness, needing to pee more often or not being able to control it, and problems with memory or concentration.

NHS inform says that in around 1 in 4 cases of MS the first noticeable symptom is a problem with one of the eyes (optic neuritis). It stresses that symptoms are common and can be caused by many conditions, so having them does not definitely mean you have MS, but it is important to get them checked.

If your GP thinks you could have MS they will refer you to a neurologist. The NHS says there is no single test to diagnose MS. Tests you may have include checks on movement, coordination, vision, balance and reflexes, blood tests, an MRI scan to look for damage to the nerves in the brain or spinal cord, a lumbar puncture to take a small sample of spinal fluid, and tests that measure how quickly messages from your eyes or ears reach the brain.

The NHS describes 3 main types: relapsing remitting, secondary progressive and primary progressive. It may take some time to work out which type you have.

There is currently no cure, but the NHS says there are treatments that can slow the progression of MS and help ease symptoms, such as steroid medicine for relapses, disease-modifying therapies to reduce how many relapses you have and how serious they are, and support from MS nurses, neurologists, physiotherapists and occupational therapists.

The NHS says to call 999 or go to A&E if you have sudden weakness or numbness in one arm, loss or blurring of vision, or problems with balance and coordination, as these could be signs of a stroke and need urgent attention. See a GP if you think you have symptoms of MS.