Tendinitis is a condition caused by inflammation of tendons---tough cords of tissue that connect muscles to bone. Tendinitis is often caused by overuse, injury or inflammatory types of arthritis, and it can cause pain, stiffness or swelling in the affected area. While tendinitis can occur in tendons anywhere in the body, including the biceps, shoulder and Achilles tendon, the most common types occur in the wrists and fingers, according to the University of Virginia Health System.
Long Head of Biceps Tendinitis
Long head of biceps tendinitis is caused by an inflammation and irritation of the tendons in the upper biceps that connect to the shoulder. According to the American Academy of Orthopaedic Surgeons, the tendon becomes red and swollen in the early stages of the condition, causing weakness and pain in the front of the shoulder. As it worsens, the tendon and the sheath covering the tendon thicken and grow larger, causing progressively more painful symptoms. Tendon damage can lead to a tendon tear and the formation of a bulge, or "popeye," in the upper arm. Long head of biceps tendinitis commonly occurs with other shoulder conditions, including arthritis, shoulder impingement and damage to the rotator cuff tendon.
Trigger Finger and Wrist Tendinitis
Wrist tendinitis is a condition caused by inflammation of the tendons of the wrist that connect the fingers to the forearm muscles. It may be caused by overuse or repetitive or unaccustomed use of the wrist or hand that weakens muscles and leads to injury.
Trigger finger or trigger thumb is caused by an inflammation and thickening of the lining of the sheaths that enclose the tendons of the fingers. This inflammation prevents normal smooth extension and flexion, causing the affected thumb or finger(s) to lock or suddenly "trigger," according to the University of Virginia Health System.
De Quervain's Tendinitis
De Quervain's tendinitis is a type of tendinitis that occurs when the tendons around the base of the thumb---and, often, the sheath surrounding these tendons---become thickened, irritated or constricted. According to the American Academy of Orthopaedic Surgeons, it commonly occurs among pregnant and middle-aged women, and may be caused by overuse or inflammatory types of arthritis such as rheumatoid arthritis. De Quervain's tendinitis causes swelling and pain along the thumb side of the wrist when forming a fist, gripping things or turning the wrist. Numbness on the back of the thumb and index finger can also develop due to irritation of the nerve on top of the affected tendon.
Achilles Tendinitis
Achilles tendinitis occurs when the Achilles tendon---the large tendon that connects the calf muscles to the heel bone---becomes inflamed or injured. Commonly caused by overuse and sports-related injuries, Achilles tendinitis causes mild to severe pain during or after running. Some people may notice sluggishness in the leg, mild swelling and stiffness that improves after the muscles in that area are warmed up, according to the American Academy of Orthopaedic Surgeons.
Rotator Cuff Tendinitis
Rotator cuff tendinitis is a condition characterized by an inflammation of the tendons in the shoulder area. According to the National Institutes of Health, injury caused by overuse of the shoulder in sports such as tennis, swimming and baseball can cause the tendons of the rotator cuff to tear, leading to pain in the shoulder during movement or at rest and weakness and discomfort when raising the arm overhead.
