Carpal Tunnel Syndrome: This is the most common cause of numbness in the hands, particularly in the thumb, index, and middle fingers. It occurs due to compression of the median nerve at the wrist.

Ulnar Nerve Entrapment: This condition affects the little and ring fingers, causing numbness, tingling, and weakness. It often results from compression of the ulnar nerve at the elbow or wrist.
Radial Nerve Compression: Although less common, compression of the radial nerve can cause numbness on the back of the hand or the thumb side of the hand.
Peripheral Neuropathy: Conditions like diabetes, vitamin deficiencies, or alcohol abuse can lead to peripheral neuropathy, which may cause numbness in the hands.
Herniated Cervical Disc: A herniated disc in the cervical spine can compress nerves that travel to the hands, leading to numbness.

Multiple Sclerosis: An autoimmune disease that can cause numbness in various parts of the body, including the hands. Early diagnosis is crucial for effective management.
Stroke or Transient Ischemic Attack (TIA): Sudden onset of numbness in one hand could be a sign of a stroke or TIA, which requires immediate medical attention.
Spinal Cord Injury or Compression: Trauma or conditions like spinal stenosis can compress the spinal cord, leading to numbness in the hands.

Guillain-Barré Syndrome: A rare autoimmune disorder that can cause rapid-onset muscle weakness and numbness in the hands and feet.
Syringomyelia: A condition characterized by the formation of a fluid-filled cavity within the spinal cord, which can cause numbness and weakness in the hands.
Vitamin B12 Deficiency: A deficiency in vitamin B12 can lead to neurological symptoms, including numbness in the hands and feet.
Lyme Disease: In rare cases, Lyme disease can cause neurological symptoms, including numbness or tingling in the hands and feet.