What are the causes of pain in the left lower back?

　　Left lower back pain may be caused by poor posture, lack of exercise, cold exposure, lumbar muscle strain, lumbar disc herniation, etc., and appropriate management can be selected based on specific circumstances. If discomfort occurs, it is recommended to seek medical attention promptly, clarify the condition, and follow medical advice for treatment to avoid delaying the condition.

　　1. Poor posture: Prolonged sitting or bending during work can keep the left side back muscles in a tense state continuously, easily causing strain and resulting in pain. Correcting poor posture, maintaining proper sitting posture during work, getting up regularly to move around, stretching the back muscles, and applying warm compresses (e.g., using a warm towel or hot water bag on the painful area for 15-20 minutes) can help improve blood circulation and relieve muscle tension.

　　2. Lack of exercise: Long-term lack of exercise can weaken the strength of the back muscles, making them unable to effectively support body weight, thus causing muscle fatigue and pain, possibly accompanied by symptoms such as back weakness and easy fatigue. It is recommended to appropriately increase physical activity, especially strength training exercises targeting the back muscles, such as sit-ups and planks.

　　3. Cold exposure: Exposure of the left side of the waist to cold environments can cause blood vessels to constrict and muscles to spasm, resulting in pain. It is important to keep the waist warm by adding clothing according to temperature changes. Traditional Chinese therapies such as moxibustion and cupping can also be used to promote circulation in the meridians, dispel cold, and relieve pain.

　　4. Lumbar muscle strain: Lumbar muscles or fascia may experience minor injuries from prolonged weight-bearing or repetitive activities, leading to inflammatory reactions and pain. Long-term lack of adequate rest and recovery can worsen symptoms. It is recommended to use medications such as acetaminophen tablets, ibuprofen tablets, or diclofenac sodium sustained-release tablets under a doctor's guidance to improve symptoms.

　　5. Lumbar disc herniation: Degeneration of the lumbar intervertebral discs, rupture of the annulus fibrosus, protrusion of the nucleus pulposus, and compression of the left nerve root can cause pain in the left posterior waist area, possibly accompanied by radiating pain, numbness, or weakness in the lower limbs. Patients may follow medical advice to use medications such as celecoxib capsules, mecobalamin tablets, or Yaotongning capsules to alleviate discomfort.

　　In daily life, it is recommended to maintain correct sitting and standing postures, keeping the lower back straight and avoiding staying in the same posture for prolonged periods.