Stop and get medical help
If you get chest pain or pressure, feel faint or dizzy, are unusually breathless, or your heart races or beats irregularly during exercise, as our plans advise.
Call 999 (911 in the US)
For chest pain that comes on suddenly and doesn't go away, feels tight or like squeezing, spreads to your arms, neck, jaw, stomach or back, or comes with sweating, feeling sick, light-headedness or breathlessness; severe difficulty breathing; someone who faints while exercising; palpitations that don't go away, or come with chest pain, shortness of breath or feeling faint; or a headache that starts suddenly and is extremely painful, especially while lifting or straining, or comes with numbness or weakness, difficulty speaking or loss of vision. The NHS says a bleed on the brain may be more likely when lifting something heavy. Don't drive yourself to A&E.
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After a fall or injury
Call 999 or go to A&E after an injury (don't drive yourself) if the arm, wrist or hand is numb, tingling or has pins and needles; a bone is sticking out or a bad cut is bleeding heavily; or the wrist, thumb or a finger has changed shape, is at an odd angle, or has turned blue, grey, white or cold.
Call 999 or go to A&E: sudden, severe pain in a muscle of the forearm or hand, which may be worse when you stretch it, with swelling, numbness, weakness or pins and needles, or tightness or difficulty moving the fingers. This can be acute compartment syndrome, which needs surgery as soon as possible. It usually follows an injury, a crush, or a cast or bandage that is too tight. Do not drive yourself to A&E.
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Same day
Same day (NHS 111): severe wrist pain; you feel faint, dizzy or sick from the pain, or you feel unwell, hot, cold or shivery; you heard a snap, grinding or popping noise when you hurt it; you can't move your wrist or hold things; your wrist has changed shape or colour; a lump on your wrist is very painful, hot or red (redness may be harder to see on brown and black skin); or you have lost the feeling in part or all of your hand. These might be signs of a broken wrist or an infection.
Same day: after a fall onto an outstretched hand, pain or tenderness at the base of the thumb on the back of the wrist (the hollow called the snuffbox), even if the wrist moves well or the first X-ray was normal. A broken scaphoid can hide on the first X-ray and is slow to heal if it's missed, so ask what follow-up is planned.
Same day: you have lost the feeling in part or all of your hand.
Same day (urgent GP appointment or NHS 111): sudden, severe pain in one joint, with swelling, a change in skin colour or difficulty moving it, especially if you feel unwell, hot, cold or shivery or have a high temperature (although not everyone has one). It could be an infection in the joint, gout or calcium crystals (pseudogout), and only a sample of fluid from the joint can tell them apart.
Same day after a fracture: the cast feels too tight, or the fingers are numb, swollen, blue or white.
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Both hands numb or clumsy
Same day: both hands numb or clumsy (dropping things, trouble with buttons or handwriting), especially with unsteady walking or falls. Pressure on the spinal cord in the neck can do this, and it is often first mistaken for carpal tunnel syndrome.
Sudden weakness on one side
Call 999, even if it passes: sudden weakness or numbness in one arm, with a drooping face or slurred speech. These are signs of a stroke.
A pop while pressing or pulling
A pop or tearing at the front of the armpit or chest during a lift, followed by bruising into the chest or upper arm, a change in the shape of the chest or armpit, or weakness pushing, can be a torn chest tendon. Don't wait for it to settle: get help the same day from NHS 111 or an urgent treatment centre, as our pec strain guide explains.
A sudden pop at the front of the elbow during a heavy pull, with bruising, a gap at the front of the elbow or a bulge in the upper arm, can be a torn biceps tendon. Go to an urgent treatment centre or A&E (in the US, urgent care or the emergency department), and don't wait for it to settle: repair is best done within the first 2 to 3 weeks.
See a GP
Not improved after 2 weeks of looking after it at home, getting worse, keeps coming back, or stopping you doing normal activities. In many areas you can refer yourself to NHS physiotherapy.
Any tingling or loss of feeling in the hand or wrist.
Carpal tunnel symptoms that are getting worse, not going away, or not helped by treatment at home; sooner if the thumb is weak or the muscle at the base of the thumb looks thinner.
See a GP if your wrist is painful, warm, swollen and stiff, or you have wrist pain and also feel unwell with a high temperature.
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After a fracture or operation
After an injury or operation, pain that is getting worse instead of better or far worse than you'd expect, with swelling, colour or temperature changes, or skin that is very sensitive to touch: contact your fracture clinic, physiotherapist or GP promptly. It can be complex regional pain syndrome (CRPS), and early treatment may help.
A nerve or the joint, not a muscle
Burning, tingling, numbness or pins and needles down an arm or leg while stretching usually means a nerve is under tension, so ease off to a position without it. A pinch at the front of the hip or ankle at the end of a stretch is the joint, so work below it. See a GP or physiotherapist if either keeps happening (our suggestion).
Very flexible joints
See a GP if you think you or your child have joint hypermobility syndrome, for example joints that keep dislocating, ongoing joint or muscle pain and stiffness, frequent sprains, tiredness even after rest, poor balance or thin, stretchy skin. A GP may check your Beighton score, arrange tests to rule out other conditions and refer you to a physiotherapist.
Slowly and with control, in the middle of your range, stopping short of locking your knees or elbows or hanging at the end of a joint's range. If a joint feels about to slip, stop or make the movement smaller (our editorial rule, the same as in our shoulder dislocation guide).
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During any session
Stop straight away if you feel any pain or become unwell, the NHS says, and contact 111 if your symptoms worry you or don't go away.
Some discomfort during these exercises is fine and doesn't mean you are doing damage. Keep it to about 5 out of 10 or less. It should settle within half an hour or so, and your hand should be no worse the next morning. If it is, do fewer, smaller or lighter next time, not nothing. An NHS wrist rehabilitation booklet uses the same limit: an unpleasant stretch of about 5 out of 10 that settles within 30 minutes.
Don't rest the hand completely for long, either: for repetitive strain, the NHS says resting for more than a few days makes the area weaker and less flexible. If a joint becomes hot, red and swollen, stop and get it checked.
A dull ache in your muscles for a day or two after something new is normal. Joint pain that's sharp, gets worse during a set or lingers into the next day means switching to the easier option, and seeing a GP or physiotherapist if it carries on (our plans' rule). Our muscle soreness guide has more.
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Ask for an urgent GP appointment or call NHS 111
Ask for an urgent GP appointment or get help from NHS 111 for a headache that's triggered or made worse by coughing, sneezing, bending down or exercising. In the US, contact your doctor or urgent care.
Check first
Speak to your GP first if you haven't exercised for some time or have medical conditions or concerns, as the NHS advises. Get advice before heavy lifting or hard straining work if your blood pressure is uncontrolled, or you have heart disease or chest pain when you're active, a pacemaker or defibrillator, diabetic eye disease, glaucoma, a hernia, recent eye or tummy surgery, or you're pregnant, as our breathing guide lists. After a recent shoulder dislocation or shoulder surgery, follow our shoulder dislocation guide or your surgical team first.
Speak to a GP first if you haven't exercised for some time, or if you have a medical condition or concerns. Get advice first, too, if you have a health problem, an injury or symptoms, have recently had a heart attack or an operation, or are pregnant or have recently given birth.
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A heart condition or high blood pressure
If you have a heart condition, follow your cardiac team's advice on how hard to work, and stop for the warning signs above. People with long-term conditions may wish to ask their specialist before starting. With uncontrolled high blood pressure, avoid straining against a held breath; the high blood pressure guide has more.