Tendinitis or Tenosynovitis: This condition is likely due to the repetitive strain on the tendons and synovial sheaths from lifting and gripping activities, leading to inflammation and pain.

Carpal Tunnel Syndrome: Compression of the median nerve can cause pain, numbness, and weakness in the arm and hand, especially with activities that involve gripping.
Thoracic Outlet Syndrome: Compression of the nerves and/or blood vessels that pass through the thoracic outlet can cause pain and numbness in the arm, exacerbated by lifting.
Strain or Sprain: Overstretching or tearing of the muscles or ligaments in the arm can cause pain, especially with lifting and gripping.

Acute Coronary Syndrome or Myocardial Infarction: Although less common, arm pain can be a referred symptom of cardiac issues, and it is crucial to rule out these life-threatening conditions, especially if accompanied by other symptoms like chest pain or shortness of breath.
Cervical Radiculopathy: Compression of the nerve roots in the cervical spine can cause arm pain, numbness, and weakness, and it is essential to consider this diagnosis to avoid missing a potentially serious condition.

Pancoast Tumor: A rare type of lung cancer that can cause arm pain due to compression of the nerves and blood vessels.
Osteoid Osteoma: A benign bone tumor that can cause nocturnal pain, which may be exacerbated by lifting and gripping.
Complex Regional Pain Syndrome: A chronic pain condition characterized by severe, burning pain, usually in one arm or leg, which can be triggered by injury or trauma.