Hamstring injury: symptoms, treatment and how long it takes to heal

The hamstrings are the muscles at the back of the thigh. The NHS says you can injure them when playing sports or exercising, and that mild injuries can usually be treated yourself.

Northern Care Alliance NHS Foundation Trust explains that a pulled hamstring (also called a hamstring tear or strain) is when the hamstring muscle group on the back of the thigh is torn. It usually occurs when the muscle is contracted while in a stretched position, often during running or sprinting, or stretching such as in gymnastics or martial arts.

The NHS says you may feel a sharp pain in the back of your leg as the hamstring is damaged. If the injury is severe, you may also feel a snapping sensation or hear a pop. After the injury the back of the thigh may feel tender to the touch and become swollen and bruised after a few hours, and you may have difficulty standing or walking on the affected leg.

Northern Care Alliance describes the first sensation as sudden pain at the back of the thigh, sometimes with a tearing sensation. In minor tears you may be able to carry on with slight pain, but as the muscle cools down the pain may gradually worsen as bleeding and swelling occur within the muscle.

• Sudden sharp pain at the back of the thigh.

• A snapping sensation or a pop in severe injuries.

• Tenderness, then swelling and bruising after a few hours.

• Spasm, weakness and reduced range of movement.

• Difficulty standing or walking on the injured leg.

The NHS says mild to moderate hamstring injuries can be treated yourself. For the first 2 to 3 days it advises PRICE therapy.

To help prevent swelling, the NHS says to try to avoid heat (such as hot baths and heat packs), massages and drinking alcohol for the first 3 days. Northern Care Alliance likewise says that in the first few days you should not do activities that increase blood flow to the injury, including hot showers, hamstring stretches, heat rubs, massage, alcohol and excessive use of the leg, because these can prolong muscle bleeding and exaggerate swelling, leading to more pain and a longer recovery.

When you can move your leg without pain stopping you, the NHS says to try to keep moving it so the hamstring does not become stiff. Northern Care Alliance suggests that early weight bearing has been shown to help sprains heal more quickly, and advises regular paracetamol and ibuprofen if suitable, checking with a pharmacist if you cannot take them.

The NHS says mild hamstring injuries usually get better in a few days, and that severe hamstring injuries can take weeks or months to heal and may need treatment from a specialist. Surgery may be needed for the most serious injuries, where there has been a complete tear of the muscle, and it takes several months to recover afterwards.

Northern Care Alliance says that with the correct treatment most hamstring muscle strains heal in up to 8 weeks. It adds that a proportion of injuries cause longer-term effects, usually if the initial management is poor or the muscle damage is significant, and that poor management can lead to a tight or weakened muscle group that is prone to re-injury when returning to activity.

The NHS says that if the injury is taking longer to heal than expected, or if you have had previous hamstring injuries, you may need to see a physiotherapist. There may be specific exercises that can speed up recovery and prevent further injury. You can get physiotherapy for free on the NHS, but there may be a long waiting list, and staff at your GP surgery may be able to advise you how to get NHS physiotherapy in your area.

Northern Care Alliance says both stretching and strengthening exercises are important. During the acute stage immediately after a strain no stretching should be done at all, only rest; this usually lasts 2 to 4 days depending on severity. You can usually begin stretching when daily activities such as normal walking are pain-free, starting with very gentle static stretches that are not painful. Strengthening begins gently with isometric contractions and progresses to more advanced hamstring exercises, always pain-free, and eventually to sports-specific drills.

The NHS says to get help from NHS 111 if you think you have injured your hamstring and any of the following apply.

• It is very painful, or the pain is getting worse.

• There is a large amount of swelling or bruising, or it is getting worse.

• It hurts to walk or stand using the injured leg.

• Your leg feels very stiff or is difficult to move.

• It is not feeling any better after treating it yourself.

• You have a very high temperature or feel very hot but also cold and shivery, which could be signs of infection.

The NHS says it is especially important to follow this advice if you have had a hamstring injury before.

• Improve your fitness gradually if you have not done much exercise in a while, and avoid strenuous sports such as football until you are fit enough.

• Warm up before exercising, which helps keep the muscles flexible.

• Stop any sport or exercise if you start to feel pain in the hamstrings.

• Do not exercise if you are feeling tired, as you are more likely to be injured when the muscles are tired.

Northern Care Alliance notes that referred pain, caused by problems elsewhere such as the lower back and hip but felt at the back of the leg, may increase the likelihood of a hamstring strain and should be considered, particularly if you have recurrent hamstring strains.

The NHS says that if you have had previous hamstring injuries, or an injury is taking longer to heal than expected, you may need to see a physiotherapist, who can look at the cause and show you specific exercises.

Most hamstring injuries are managed at home with advice from a pharmacist. The NHS says a pharmacist can give advice on suitable treatments to relieve pain, and NHS 111 can advise if symptoms are worrying. Physiotherapy is available on the NHS, sometimes by self-referral to local MSK services.

Some people choose private physiotherapy or a sports medicine opinion for faster access, especially if they play sport regularly. The principles of care are the same.