Carpal tunnel syndrome occurs when the median nerve is compressed as it passes through a narrow tunnel at the wrist. Symptoms may initially come and go but can become persistent when nerve compression progresses.

Possible symptoms may include:

• Tingling or numbness in the thumb, index and middle fingers

• Hand or wrist pain, often worse at night

• Weakness of the thumb

• Difficulty gripping or holding objects

• Reduced hand dexterity or frequently dropping objects

Management may include activity modification, wrist splinting, medication, injection or surgical decompression, depending on symptom severity and nerve function.

The ulnar nerve can become compressed around the elbow, commonly called cubital tunnel syndrome, or less frequently at the wrist. Persistent compression can affect sensation and the small muscles of the hand.

Possible symptoms may include:

• Tingling or numbness in the little and ring fingers

• Pain around the inner elbow or forearm

• Symptoms aggravated by bending the elbow

• Weak grip or difficulty with fine hand movements

• Wasting of the small hand muscles in advanced cases

Treatment is planned according to the site and severity of compression and may include activity modification, splinting, therapy or surgical decompression.

Peripheral nerves may become compressed at different locations in the arm or leg. Examples include radial, peroneal and other nerve-entrapment syndromes.

Possible symptoms may include:

• Localised burning or electric-shock-like pain

• Tingling or numbness along the affected nerve

• Weakness of specific muscles

• Difficulty lifting the wrist, foot or toes

• Symptoms aggravated by particular positions or movements

Clinical examination and nerve testing may help identify the affected nerve and the location of compression.

Peripheral nerves may be injured by cuts, fractures, dislocations, traction injuries, injections or other trauma. The degree of recovery depends on whether the nerve has been bruised, stretched, compressed or divided.

Possible symptoms may include:

• Loss of sensation following an injury

• Burning, shooting or electric-shock-like pain

• Weakness or loss of movement

• Reduced grip or difficulty using the affected limb

• Progressive muscle wasting

Early assessment is important when weakness or loss of sensation develops after trauma. Management may involve observation, rehabilitation, nerve testing or surgery, depending on the nature and severity of the injury.

The brachial plexus is a network of nerves that supplies movement and sensation to the shoulder, arm and hand. It may be injured through road-traffic accidents, falls, traction injuries or other trauma.

Possible symptoms may include:

• Weakness or paralysis of part or all of the arm

• Loss of sensation in the arm or hand

• Severe burning or electric-shock-like pain

• Reduced shoulder, elbow, wrist or hand movement

• Muscle wasting over time

Assessment may require detailed neurological examination, nerve-conduction studies, electromyography and imaging.

Tumours can arise from the coverings of peripheral nerves. Many are benign, but they may cause symptoms by enlarging or pressing on the affected nerve.

Possible symptoms may include:

• A lump along the course of a nerve

• Localised pain or tenderness

• Tingling or electric-shock-like pain when the swelling is touched

• Numbness or altered sensation

• Weakness in the affected limb

Management depends on the tumour’s location, imaging appearance, growth, symptoms and relationship to the functioning nerve.