Biceps tendonitis is a painful condition resulting from inflammation or irritation of the biceps tendon at the shoulder or elbow. It commonly occurs due to overuse or sudden exertion, leading to symptoms such as pain, tenderness, and swelling in the affected area. Treatment may involve rest, applying ice, taking anti-inflammatory medication, and performing specific exercises to stretch and strengthen the affected tendon. In some cases, corticosteroid injections or physical therapy may be recommended. Seeking medical evaluation is essential to determine the appropriate management and prevent worsening of the condition.