DVT vs pulled calf muscle: why calf pain should not be guessed at

You cannot reliably tell a DVT from a pulled calf muscle by feel or by looking at the leg at home, and the NHS does not suggest that you try. A strain tends to come with an event: a sprint, a jump, a stumble, a change of exercise. The NHS describes pain, tenderness or weakness in the muscle, with swelling or bruising. A DVT may come on without any injury, with throbbing pain and swelling in one leg, and it is more likely if you have recently had surgery, been immobile, travelled for hours or have another risk factor.

Because the consequences of missing a DVT can be severe, the safe rule is this: if calf pain and swelling have no clear cause, are getting worse, or come with risk factors, have it assessed rather than waiting. If there is breathlessness or chest pain as well, that is an emergency.

The NHS lists symptoms of DVT in the leg as throbbing pain in 1 leg, usually in the calf or thigh, swelling in 1 leg, red, blue or darkened skin around the painful area (which may be harder to see on brown or black skin) and swollen veins. Both legs are rarely affected. Sometimes the only symptom is pain in the lower tummy, which is a rare sign of pelvic vein thrombosis, and symptoms can occur in an arm.

The NHS says a DVT is more likely to happen if you are over 60, overweight, smoke, have had DVT before, take HRT or oestrogen-containing contraception, or have cancer, heart failure, varicose veins, thrombophilia, inflammatory bowel disease or vasculitis. There are also times when the chance is higher, such as staying in or recently leaving hospital, surgery, being confined to bed for 3 days or more, a long journey of more than 4 hours, pregnancy or the 6 weeks after having a baby, and dehydration. Sometimes DVT happens for no obvious reason.

The NHS says sprains and strains are common injuries affecting the muscles and ligaments, and most can be treated at home. A strain is an overstretched or torn muscle, also called a pulled muscle, and is most common in the feet, legs and back. It is likely to be a sprain or strain if you have pain, tenderness or weakness, the area is swollen or bruised, you cannot put weight on it or use it normally, or you have muscle spasms or cramping.

For the first 2 to 3 days the NHS suggests PRICE therapy: protection, rest, ice for up to 20 minutes every 2 to 3 hours, compression with a bandage and elevation. It says to avoid heat, alcohol and massage for the first couple of days. After 2 weeks most sprains and strains will feel better, strenuous exercise such as running should be avoided for up to 8 weeks because of the risk of further damage, and severe strains can take months.

The NHS DVT page says to ask for an urgent GP appointment or get help from NHS 111 if you think you have DVT. If you have symptoms of DVT such as pain and swelling and also feel short of breath or have chest pain, it says to call 999 or go to A&E, and not to drive yourself, because the clot may have travelled to the lungs. If you are pregnant, an early pregnancy unit or maternity unit can be called.

If you think you have strained a muscle and the pain is very bad, getting worse, with a large amount of swelling or bruising, or you cannot put weight on the leg or walk more than a few steps, the NHS advises NHS 111. It also advises 111 for an injury that is not feeling better after treating it yourself or that comes with a very high temperature or feeling hot, cold or shivery, which could be an infection.

Diagnosis of DVT is by ultrasound scan, which the NHS says should happen within 24 hours of a doctor suspecting it. Treatment is blood-thinning medicines, usually tablets such as rivaroxaban for at least 3 months, and during pregnancy blood-thinning injections.