Carpal Tunnel Syndrome: This condition is characterized by pain, numbness, and weakness in the hand, particularly along the thumb and the medial aspect of the wrist, due to compression of the median nerve. The symptoms described match closely with carpal tunnel syndrome, making it the most likely diagnosis.

De Quervain's Tenosynovitis: This condition affects the tendons on the thumb side of the wrist, leading to pain and tenderness, especially when forming a fist, grasping, or turning the wrist. It could explain the pain and weakness, especially if the activities exacerbate the symptoms.
Wrist Ganglion Cyst: A ganglion cyst is a noncancerous lump that can develop on the wrist, causing pain, weakness, and sometimes numbness if it presses on a nerve. The location of the pain and the presence of weakness could suggest a ganglion cyst affecting nerve function.
Radial or Ulnar Nerve Compression: Compression of these nerves can lead to pain, weakness, and numbness in the hand and wrist. Depending on which nerve is compressed, the symptoms can vary but could include the area described.

Acute Compartment Syndrome: Although less common, this is a medical emergency where increased pressure within a muscle compartment leads to inadequate blood supply to the tissues inside the compartment. It causes severe pain, especially on palpation, and can lead to weakness and numbness. Missing this diagnosis could result in permanent damage.
Infections (e.g., Cellulitis, Abscess): Infections in the hand or wrist can cause pain, swelling, redness, and weakness. They require prompt treatment to avoid serious complications.
Fracture or Dislocation: Traumatic injuries to the wrist or hand can cause pain and weakness. Some fractures or dislocations might not be immediately apparent on physical examination, especially if they are non-displaced.

Tumor (Benign or Malignant): Tumors in the wrist or hand can cause localized pain and weakness. While rare, they are an important consideration in the differential diagnosis, especially if the pain is persistent and unexplained by more common conditions.
Arthritis (Rheumatoid, Psoriatic): Certain types of arthritis can cause pain, swelling, and weakness in the hands and wrists. While not as common as other diagnoses, they should be considered, especially if there are systemic symptoms or a family history.
Neuropathies (e.g., due to Diabetes): Systemic conditions like diabetes can cause neuropathies that affect the hands and wrists, leading to pain, numbness, and weakness. These conditions might be rare in the context of localized wrist and hand pain but are important to consider in patients with relevant medical histories.