Muscle strain or injury: Overexertion, heavy lifting, or poor posture can cause localized pain in the left shoulder, arm, back, or leg.
Nerve-related pain: Conditions like sciatica or a pinched nerve in the spine can radiate pain down the left side.
2. Digestive and Abdominal Issues
Gas or indigestion: Trapped gas or acid reflux can cause discomfort on the left side of the abdomen.
Constipation or irritable bowel syndrome (IBS): Can lead to cramping or pain.
Spleen problems: The spleen is located on the upper left side and can cause pain if enlarged or injured.
3. Heart-Related Concerns
Heart attack or angina: Pain or pressure on the left side of the chest, sometimes radiating to the arm, jaw, or back, may indicate a heart problem. This requires immediate medical care.