What causes pain below the left shoulder blade?

Pain below the left scapula may be due to physiological factors, or it could result from pathological conditions such as myofascial inflammation or periarthritis (frozen shoulder). The specific analysis is as follows:

I. Physiological Causes

If the left arm has been used for prolonged periods in repetitive tasks or overexertion, muscle fatigue and excessive accumulation of acidic metabolic substances may occur. If these substances are not promptly metabolized, they can irritate surrounding tissues or nerves, causing pain. Usually, no special treatment is required; symptoms can be relieved with heat application, massage, and adequate rest.

II. Pathological Causes

1. Myofascial Inflammation

If muscles or tendons in the left arm area are chronically exposed to adverse stimuli such as cold exposure or trauma, aseptic inflammation may develop. Under stimulation by inflammatory mediators, diffuse pain and muscle spasms may occur. Physical therapies such as infrared radiation or ultrashort wave therapy can be used to improve symptoms. Analgesic medications like acetaminophen tablets or ibuprofen sustained-release capsules may also be helpful.

2. Periarthritis (Frozen Shoulder)

Periarthritis can also cause the aforementioned symptoms, primarily due to inflammation in the soft tissues surrounding the shoulder joint. Pain can be managed with analgesics such as diclofenac sodium sustained-release capsules or loxoprofen sodium sustained-release tablets, as directed by a physician. Alternatively, minimally invasive needle-knife release surgery may be considered.

In addition to the above common causes, cervical spondylosis or other conditions cannot be ruled out. It is recommended to undergo X-ray or other imaging examinations for further evaluation.