Tendonitis is inflammation of a tendon - that strong, white, fibrous tissue connecting muscle to bone. Tendonitis can be associated with a calcium deposit, which can cause inflammation. It is one of the common causes of acute pain in the shoulder and can occur after an injury or as a result of repetitious movements. In rare cases, it may also result from a disease. Other causes of tendonitis include:

• poorly-fitted shoes that rub against foot tendons
• bone spurs in the feet or elsewhere that irritate tendons
• obesity, which puts abnormal pressure on the legs and feet
• repeated overuse of the wrist, which can inflame the tendons
• overuse of the tendons in the shoulder, sometimes seen in swimmers or in the serving arm of a tennis player
• overuse of arm muscles, which can cause inflammation of tendons in the elbow, such as tennis or golfer’s elbow.

Tendonitis usually causes one or more of the following symptoms:

• a sharp or achy pain
• tenderness and swelling
• restricted movement in the area surrounding the injury
• weakness in the arm or leg due to pain.

In cases of achilles tendonitis, if the tendon becomes more painful with greater activity such as running or playing sports, there is a chance the tendon could rupture: if not taken care of, tendonitis can weaken tendons, making them more susceptible to a tear.

Acute tendonitis often subsides within 10 to 14 days. If the pain worsens or continues after home care for over 14 days, a doctor should be consulted.