Sprains and strains are very common injuries that affect muscles and ligaments.
They often occur when playing sports if you change direction or speed suddenly, fall and land awkwardly, or collide with an object or person.
Read more about the causes of sprains and strains.
A sprain occurs when one or more ligaments have been stretched, twisted or torn, usually as a result of excessive force being applied to a joint. Ligaments are strong bands of tissue around joints that connect bones to one another.
Common locations for sprains include the knees, ankles, wrists and thumbs. Symptoms of a sprain can include:
There may be swelling soon after the injury but the bruising may not show until later or it may not show at all.
Bruising sometimes develops away from the affected joint, as blood seeps along the muscles before surfacing to the skin.
A strain occurs when muscle fibres stretch or tear. It's usually the result of the muscle being stretched beyond its limits or forced to contract (shorten) too quickly.
Muscle strains are particularly common in the legs and back, such as hamstring strains and lumbar (lower back) strains.
Symptoms of a muscle strain can include:
Most sprains and strains are relatively minor and can be treated at home (see below).
However, you should visit a minor injuries unit (MIU) or your GP if you think you have a sprain or strain and:
If you have any of these symptoms your injury will need to be assessed by a doctor. You might have a severe sprain or strain or another serious injury, such as a fracture.
Read more about diagnosing sprains and strains.
Minor sprains and strains can usually be treated with self care techniques, such as PRICE therapy (protection, rest, ice, compression and elevation).
Generally, you should try to start moving a sprained joint as soon as it's not too painful to do so, whereas a strained muscle should normally be immobilised for at least a few days.
Ordinary painkillers, such as paracetamol, can be used to help ease any pain, although stronger medication can be prescribed if the pain is more severe.
Most people will regain full use of the affected body part within six to eight weeks, although severe injuries may take longer to heal and some people may experience persistent problems lasting several months or longer.
Read more about treating sprains and strains.
To help prevent sprains and strains you should:
Read more about preventing sprains and strains.