De Quervain's tenosynovitis is an inflammatory condition of the tendons on the side of the wrist at the base of the thumb, this inflammatory condition was first described by de Quervain in 1897, according to which the syndrome itself was named. De Quervan syndrome affects the tendons of two muscles of the thumb of the radiocarpal joint, the muscle extensor pollicis brevis and the muscle abductor pollicis longus. The syndrome most often occurs as a result of excessive strain in physical jobs, occupations and sports in which the use of a fist is common. The syndrome itself may have symptoms similar to some other conditions such as osteoarthritis, trigger finger or neuritis. In order to properly diagnose the syndrome, visual cues, palpation and provocation tests are used. The Finkelstein and Eichoff tests are used, the results show that finkelsten's test is more accurate and has a higher specificity, fewer false positives and less pain during implementation. Treatment is conservative and operational. Conservative treatment techniques imply orthoses and longets to stabilize painful segments carried out in conjunction with corticosteroid injections for better results, ultrasound therapy that improves healing, and manual and muscle-strengthening techniques and exercises. Physiotherapy methods help in the treatment of this syndrome using the use of modalities, the emphasis is on de sensitization and therapeutic exercises. Patients start exercising when the pain is small, and the strengthening program itself is gradual and progressive. The patient's pain is respected and progresses only when there are no deteriorations. The program begins with isometric exercises for the aforementioned thumb muscles, continues with eccentric exercises until the patient is not ready to do the concentric part. The final stage of rehabilitation involves exercises for the combined movements of the hand, fingers and elbow and the emphasis is on returning to the activities of everyday life with an adequate load volume to avoid the recurrence of symptoms. Surgical treatment is a choice when it has failed conservatively, the aim of surgery is to reach the affected tendons and make more room so that the pressure on the tendons themselves is reduced and that patients can return to their daily activities.