Tendinitis is irritation of a tendon, the cord that attaches muscle to bone, most often caused by repetitive movement or overuse. Common sites include the shoulder, elbow (tennis or golfer's elbow), wrist, knee, and the Achilles tendon at the heel. Symptoms include pain and tenderness near the affected joint, worse with movement, and sometimes mild swelling.
Early management usually involves relative rest from the aggravating activity, ice, and over-the-counter pain relief, followed by a gradual, guided return to activity. A physiotherapist can prescribe strengthening and loading exercises, which are often the most effective long-term treatment. Adjusting technique, equipment, or workload can help prevent recurrence.
See a doctor if pain is severe, does not improve over a few weeks, follows a sudden snap or pop (which may indicate a tendon rupture), or comes with significant swelling, redness, or warmth. Sudden severe pain and weakness in a tendon, such as being unable to push off the foot after a calf injury, needs prompt assessment.