The hand can be used as a very useful instrument that can perform very complex manipulations that require force and precision. In addition, it is specialized for touch and feeling, and it has a great role in perceiving the environment. The most important part that adds functionality to the hand is the thumb. It contributes more than other fingers during thumb grip activities. However, due to many factors such as inflammatory and neurological causes, orthopedic problems such as tendon and ligament injuries, the thumb joints may be loaded above normal. Mechanical stresses over time cause thumb pain and functional disabilities in daily life activities. Symptoms, muscle strength, normal joint movements, and functional conditions of the patients are objectively evaluated in the clinic by various methods. Patient-based questionnaires, such as The Disabilities of the Arm, Shoulder and Hand (DASH) and Michigan Hand Outcome Questionnaire, can evaluate the independence levels and performances of the patients in daily living activities. However, these questionnaires are used in all upper extremity pathologies, and there is no Turkish scale that evaluates only the function of the thumb, pain and patient satisfaction. During the clinical evaluations of patients with thumb complaints, a scale with a higher sensitivity than the DASH questionnaire, with a validity and reliability study that informs us of their performance and pain from the patients' perspective, is needed. Therefore The Thumb Disability Examination (TDX) was created by selecting the items that are suitable for the thumb from the DASH and Michigan Hand Outcome (MHQ) questionnaires. In this study, cultural adaptation of TDX to Turkish cultural will be done. In this process, the questionnaires will be translated from English to Turkish by two different people. A single Turkish translation will be created from these translations. This Turkish survey will be translated into English by two native speakers of English but who speak Turkish very well, and the English questionnaire will be compared with the original survey. In our study, the Turkish version and reliability (internal consistency, test and retest reliability) of the TDX will be evaluated. Voluntary patients who have been diagnosed in the study and applied to Hacettepe University, Faculty of Physiotherapy and Rehabilitation, Hand Surgery Rehabilitation Unit within the last 6 months will be included. Detailed information about the study to be carried out will be given to the patients face to face and if they accept, the informed consent form will be signed. DASH, SF-36, TDX, Beck Depression and Beck Anxiety, Michigan Hand Outcome Questionnaires, pain, normal joint motion, grip strength assessments will be done to patients twice, 3 days apart.The data obtained as a result of the study will help to identify the problems in patients with thumb pain and to show the effectiveness of the treatments from the patient's perspective. We considered that adding the Turkish adaptation of this questionnaire to the literature by making validity and reliability studies will contribute to clinical evaluations. The data obtained as a result of the study will help to identify the problems in patients with thumb complaints and to show the effectiveness of the treatments from the patient's perspective.