Editor-In-Chief: C. Michael Gibson, M.S., M.D. ; Associate Editor-In-Chief: Cafer Zorkun, M.D., Ph.D. ; Associate Editor-In-Chief: M.Umer Tariq  Kiran Singh, M.D. 
Synonyms and keywords: Tendon sheath inflammation; inflammation of the tendon sheath
Tenosynovitis is the inflammation of the fluid-filled sheath (called the synovium) that surrounds a tendon. Symptoms of tenosynovitis include pain, swelling , and difficulty moving a particular joint where the inflammation occurs. When the condition causes the finger to "stick" in a flexed position, this is called "stenosing" tenosynovitis, which is commonly called "Trigger Finger."
When the finger tendon is inflamed, the synovium swells. Sometimes the tendon cannot slide easily through the synovium. When you straighten your finger, the tendon locks or sticks as it squeezes through the too-small synovium.
It usually occurs with tendinitis and it is related to stenosing tenosynovitis.
Causes of trigger finger are unknown. Repeated use of hand tools can precede the condition, as well as arthritis or injury. Trigger Finger sometimes runs in families, and is generally seen more often in males than in females. The causes for children are even less known and have a recurrence rate of less than 1-5% after treatment.
(By organ system)
|Cardiovascular||No underlying causes|
|Chemical / poisoning||No underlying causes|
|Dermatologic||No underlying causes|
|Drug Side Effect||Pergolide, Pramipexole, Rasagiline|
|Ear Nose Throat||No underlying causes|
|Endocrine||No underlying causes|
|Environmental||No underlying causes|
|Gastroenterologic||No underlying causes|
|Genetic||No underlying causes|
|Hematologic||No underlying causes|
|Iatrogenic||No underlying causes|
|Musculoskeletal / Ortho||No underlying causes|
|Neurologic||No underlying causes|
|Nutritional / Metabolic||No underlying causes|
|Obstetric/Gynecologic||No underlying causes|
|Oncologic||No underlying causes|
|Opthalmologic||No underlying causes|
|Overdose / Toxicity||No underlying causes|
|Psychiatric||No underlying causes|
|Pulmonary||No underlying causes|
|Renal / Electrolyte||No underlying causes|
|Rheum / Immune / Allergy|
|Sexual||No underlying causes|
|Trauma||No underlying causes|
|Urologic||No underlying causes|
|Miscellaneous||No underlying causes|
(In alphabetical order) Other causes and associated conditions are:
History and Symptoms
- Problems moving joints
- Pain, swelling and tenderness around a joint, particularly the hand, wrist, foot, and ankle
- Pain when moving the affected joint
A physical examination shows swelling over the involved tendon. The health care provider may touch or stretch the tendon or have you move the muscle to which it is attached to see whether you experience pain. 
Possible treatments for tenosynovitis include cortisone injections (then a course of paracetomal and ibuprofen for pain) and an outpatient surgery to enlarge the synovium. The hand is splinted for a week or so.
Template:Diseases of the musculoskeletal system and connective tissue