Influenza or 'flu' is a highly infectious disease that causes unpleasant symptoms, including fever, aches, sore throat, fatigue and nausea. If you have MS, catching the flu can make your MS symptoms worse. You may notice this particularly if you find that your MS symptoms get worse in the heat.

Fluoxetine is normally prescribed to treat depression. Exploratory studies have also looked at whether it might help reduce inflammation around nerves in MS.

Foot drop, or dropped foot, is a symptom of multiple sclerosis caused by disruption in the nerve pathway between the legs and the brain. Find out how foot drop is treated in MS.

Frailty is the decline in our mental and physical resilience related to the ageing process. Find out more about frailty in this A to Z page.

Functional electrical stimulation (FES) is a treatment that applies small electrical charges to a muscle that has become paralysed or weakened, due to damage in your brain or spinal cord. The electrical charge stimulates the muscle to make its usual movement. In MS it is mostly used as a treatment for foot drop, where disruptions in the nerve pathways between the legs and brain mean the front of your foot cannot be lifted to the correct angle when walking.

FND and functional symptoms can be common in people with MS. These symptoms can be treated and reversed with therapy.

Generic and biosimilar drugs including DMDs or DMTs are becoming more common in multiple sclerosis (MS). We explain what they are and how they might be used.

People who have been diagnosed with multiple sclerosis (MS) cannot donate blood or bone marrow, however they can be considered as organ donors. Learn more in this A-Z entry.

Glial cells are the support network for your nerve cells. They provide energy and myelin to allow the neurons to work. Find out more about glia in MS in this A-Z entry.