What causes side pain?

Side pain can be caused by a wide variety of mild to serious diseases, disorders and conditions. Relatively mild conditions that can cause side pain include indigestion and exercising too much. Serious and life-threatening conditions that can cause side pain include heart attack and trauma.

Urinary causes of side pain

A common source of side or flank pain is kidney disease and other conditions of the kidney including:

  • Kidney abscess

  • Kidney cancer

  • Kidney infarction (death of kidney tissue due to lack of oxygen)

  • Kidney infection (pyelonephritis)

  • Kidney stones

  • Kidney trauma

  • Ureteral obstruction (acute or chronic) due to such conditions as a congenital anomaly, blood clot, or kidney stone

Gastrointestinal causes of side pain

Side pain may occur by itself or in conjunction with abdominal pain due to diseases and conditions of the digestive tract including:

Lung-related causes of side pain

Side pain can be caused by serious problems with the respiratory system. Although the following conditions may be most commonly associated with pain centered in the chest, the pain can radiate to the side of the chest, ribcage or back in some cases. Respiratory conditions include:

  • Asthma

  • Bronchitis

  • Chronic obstructive pulmonary disease (COPD; includes emphysema and chronic bronchitis)

  • Pleurisy (inflammation of the lung lining)

  • Pneumonia

  • Pneumothorax or hemothorax (collapsed lung or blood around the lung)

  • Pulmonary edema (buildup of fluid in the lungs)

  • Pulmonary embolism (blood clot that travels to the lung)

  • Pulmonary hypertension (high blood pressure in the arteries of the lungs)

  • Tuberculosis (serious infection affecting the lungs and other organs)

Gynecological causes of side pain

Female reproductive organs may become inflamed, infected, or otherwise damaged, causing pain on one or both sides of the lower abdomen above the groin. Gynecological causes of side pain include:

  • Ectopic pregnancy

  • Ovarian cysts or rupture of ovarian cysts

  • Ovulation

  • Salpingitis (inflammation of the fallopian tubes)

  • Tubo-ovarian abscess (abscess affecting an ovary and fallopian tube)

Cardiovascular causes of side pain

Side pain, possibly in conjunction with abdominal or chest pain, can arise from serious or life-threatening problems with the heart and the vascular system. Although the following conditions are often associated with frontal chest pain, the pain can radiate to the side of the chest, ribcage or back in some cases. Cardiovascular conditions include:

  • Abdominal aortic aneurysm

  • Aortic dissection

  • Congenital cardiac anomalies, disorders, and birth defects, such as coarctation of the aorta and aortic valve stenosis

  • Congestive heart failure

  • Coronary artery disease (heart disease) including coronary artery spasm or angina due to atherosclerosis (hardening and narrowing of the arteries)

  • Endocarditis (inflammation or infection of the inner lining of the heart)

  • Heart attack

  • Mitral valve prolapse and other heart valve problems

  • Pericarditis (inflammation or infection of the lining that covers the heart)

  • Thoracic aortic aneurysm

Other causes of side pain

Other causes of side pain include:

  • Exercise

  • Fibromyalgia (chronic condition that causes pain, stiffness and tenderness)

  • Hernia

  • Muscle spasm

  • Musculoskeletal injuries, such as a rib fracture or strained muscle in the chest wall, back, or abdomen

  • Neuritis (inflammation of a nerve between ribs)

  • Rib infection

  • Seminal vesiculitis (seminal vesicle inflammation)

  • Shingles (herpes zoster infection)

Questions for diagnosing the cause of side pain

To diagnose the underlying cause of side pain, your doctor or licensed health care provider will ask you questions about your symptoms. You can best help your health care provider diagnose the underlying cause of side pain by providing complete answers to these questions:

  • When did the pain start?

  • Do you feel pain on one side or both sides?

  • Does the pain go from your side to another part of your body such as your groin, abdomen or chest?

  • Have you been injured recently?

  • How would you describe the pain? Examples include cramp-like, dull, sharp, constant, and intermittent.

  • What medications have you recently taken?

  • What other symptoms do you have?

What are the potential complications of side pain?

Complications of the underlying causes of side pain vary. Any kind of unexplained or persistent side pain, whether it occurs alone or is accompanied by other symptoms, should be evaluated by your doctor or health care provider. Once the underlying cause is identified, following the treatment plan you and your health care provider develop specifically for you will minimize the risk of complications of serious or life-threatening underlying causes of side pain including:

  • Cardiac arrest

  • High carbon dioxide levels and acidosis

  • Injury to organs and structures in your chest and abdomen including your arteries, kidneys, lungs, liver and spleen

  • Respiratory failure and respiratory arrest

  • Sepsis

  • Shock

  • Spread of cancer

  • Spread of infection


  1. Bueschen, Anton J. Flank pain. In: Walker HK, Hall WD, Hurst JW, eds. Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd ed. Boston: Butterworths; 1990: Chapter 182. http://www.ncbi.nlm.nih.gov/books/NBK292/
  2. Chest pain. Medline Plus, a service of the National Library of Medicine National Institutes of Health. http://www.nlm.nih.gov/medlineplus/ency/article/003079.htm
  3. Flank pain. PubMed Health, a service of the NLM from the NIH. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0003600/
  4. NINDS Back Pain Information Page. http://www.ninds.nih.gov/disorders/backpain/detail_backpain.htm
  5. Ribcage pain. PubMed Health, a service of the NLM from the NIH. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0003596/.

What is side pain?

Side pain is discomfort that occurs on the left or right side of the torso between the armpits (axilla) and the hips. These general areas contain bones, muscles, nerves, blood vessels, organs, and other structures that can become infected, inflamed or damaged.

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What other symptoms might occur with side pain?

Side pain may accompany other symptoms, which vary depending on the underlying disease, disorder or condition.

Digestive symptoms that may occur with side pain

Side pain may accompany symptoms affecting the digestive tract including:

Medical Reviewer: Cynthia Haines, MD Last Annual Review Date: Aug 8, 2013 Copyright: © Copyright 2014 Health Grades, Inc. All rights reserved. May not be reproduced or reprinted without permission from Health Grades, Inc. Use of this information is governed by the HealthGrades User Agreement.

This Article is Filed Under: Bones, Joints and Muscles

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