Underarm pain: What are the possible causes?

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Various conditions can trigger underarm pain. The armpit is a usual site for enlargement of the lymph node. Other edifices in or adjacent the armpit can cause pain or discomfort.

In some cases, it might be due to traumatic injury, certain medical conditions or nervous system ailments. Some forms of pain might require medical care to help resolve the underlying cause.

Common causes of underarm pain

Brachial plexus injury

Brachial plexus injury can trigger underarm pain. The brachial plexus is a system of nerves positioned in the neck as well as the shoulder which also travel via the armpit. There are instances in which this network of nerves can be impaired by stretching, pressure or trauma.

Brachial plexus injury can trigger underarm pain.

The common form of brachial plexus injury is traction of the brachial plexus nerve. This occurs if the head and neck are driven away from the shoulder, towards the opposite side. In severe cases, the nerves might rip apart from the roots in the cervical neck or spine.

Shoulder dislocation

Shoulder dislocation is a common injury that can cause underarm pain. If an individual has this injury, the upper arm bone head is fully dislodged out of the shoulder socket. The usual indications of this injury include numbness, swelling, weakening and discoloration in the involved shoulder and underarm.


Lymphadenitis involves infection of the lymph nodes or glands. This is a usual complication of some forms of bacterial infection.

The condition can affect any lymph node including the axillary lymph nodes. The usual indications linked with lymphadenitis include tender, swollen and hardened lymph nodes as well as tender, reddened skin over the affected nodes.

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