What should you know about external rhabdomyolysis?

The word external describes a trigger outside the muscle itself, such as unusually intense exercise, a crush injury, heat exposure, or pressure from being unable to move for a long time. Damaged muscle may cause marked soreness, weakness, swelling, or reduced movement. Urine can become unusually dark, although this sign may be absent. This is different from ordinary muscle soreness after exercise, which is usually milder and settles with rest.

Stop strenuous activity and move to a cool place if heat or exertion was involved. Do not massage a very swollen or painful area. Sip fluids only if you are awake, able to swallow, and have not been told to restrict fluids; do not force large amounts. Arrange urgent medical evaluation, because clinicians may check blood chemistry, kidney function, urine, and the extent of muscle injury. Tell them about exercise, heat, injury, medicines, supplements, or substances taken before symptoms began.

Seek emergency care for severe weakness, confusion, fainting, trouble breathing, very little urine, dark urine with significant muscle pain, rapidly increasing swelling, or pain that seems far greater than expected. Emergency assessment is also appropriate after a crush injury, prolonged immobilisation, or heat illness. Do not wait for urine colour to change before seeking help.

Ask what may have triggered the muscle injury, which tests are needed, whether your kidneys need monitoring, how much activity and fluid are appropriate, and which medicines or supplements should be paused.