<s>[INST]I ve had the flu for 5 days. Today I have a pain in the left side of my back. It feels like a muscle cramp, but I am leary. I had a similar symptom three years ago when I had a heart attack two days after a tripple bypass, due to an arterial disection during a heart cath. Should I be concerned or wait to see if it clears up?[/INST]Hi sir/madam, Thanks for your question on Chat Doctor. Common Causes of Lower Left Back Pain:-1. Bulging or herniated discs.2. Muscle spasms.3. Pulled back muscle.4. Muscle imbalances.5. Muscle strain, injury or trauma to the back muscles, ligaments or joints.6. Trigger points.7. Stress / Negative emotions. If lower left back pain is particularly severe, it may be an indication of a herniated or ruptured disc, or sciatica. Recommended Treatments for Lower Left Side Back Pain:-1. Muscle Balance Therapy.2. Massage Therapy.3. Trigger Point Therapy.4. Inversion / Decompression Therapy.5. Acupuncture / Acupressure.6. Use a Back Support or Cushion.7Relaxation, Meditation.8. Dietary improvements (i.e. reducing foods that cause inflammation like dairy, wheat / gluten, sugar, nightshades).9. Chat Doctor. Left Side Back Pain Prevention:-1. While walking and sitting, keep a relatively upright posture2. When lifting objects (heavy or light), always lift with the legs-never bend from the waist3. Exercise; focus on working out the muscles in the core (abdomen and back)4. Daily Stretching. Hope I was helpful. Have a healthy day.</s>