Back Pain on the Left Side: Possible Causes

Suffers from back pain on the left side? Did you know that the back pain on the left side, especially in the lower part of the back, is considered the most common?

The back pain on the left side, in the likeness of the right side of the back, have as possible causes of the injury in the soft tissues (muscles, ligaments and/or tendons), injury on various structures of the spine (such as the facet joint, discs, nerve roots), and conditions or diseases that affect the internal organs.

In some cases the back pain on the left side may represent a medical emergency. When the pain is accompanied of the following symptoms may be facing a more serious problem:

  • The intense pain and sudden in the back that does not diminish with rest;
  • Dizziness, confusion or shortness of breath;
  • Pain that worsens at night;
  • Fever persistent or sporadic, and chills;
  • Nausea or vomiting;
  • Painful urination or blood in the urine;
  • Loss of control in the bladder and/or intestines;
  • Unexplained significant loss of weight;
  • Significant weakness, numbness, or tingling in the lower part of the body.

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Any one of these symptoms can signal an underlying condition severe and warrants immediate medical attention.


The majority of back pain comes from the muscle, and the same goes for when the pain is located preferably on the left side of the back. The main causes of muscle pain include activities that require lifting, repeated and transportation of heavy objects, awkward postures prolonged sitting or standing, awkward postures, incorrect and other habits that end up overloading the muscles.

Being overweight, and present a abdominal muscles weak also significantly increases the risk of muscle injury, as well as other structures in the spine. The ligaments are also a source of pain, or suffering an excessive stretching or even rupture partial or complete.

Such as was studied in the article of the possible causes of back pain on the right side, the causes of pain on the left side relative to the soft tissues and structures of the spine are similar. Therefore the herniated disk, osteoarthritis, stenosis of the spinal canal, the dysfunction of the sacroiliac joint, when they occur to the left can also cause pain in this side of the back.

Other conditions related to the structures of the spine such as fracture, ankylosing spondylitis, fibromyalgia, tumors, among others, may also be at the origin of the back pain on the left side.

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Back pain during pregnancy is very common, especially in the lumbar spine, and can manifest itself preferentially on the left side. As your baby increases in size, the uterus can compress the structures sensitive to pain, including the nerves. It is not uncommon, for example, that the pregnant patients complaining of a pain that runs through the buttock and leg due to compression of the sciatic nerve.

Kidney problems, such as kidney stones or infection or kidney, ulcerative colitis, gynecological diseases, the causes are discussed in the article on the back pain on the right side, can also be a source of pain in the back on the left side.

Tumors, benign or malignant, may also be at the origin. These tumors may be primary tumors originating in the pelvis, to the bones of the spinal column or spinal cord, or metastatic malignancies that originate in another location. The tumors can cause localized pain, severe pain and even loss of muscle function.

The pancreatitis, a condition that involves the inflammation of the pancreas, can cause pain in the upper abdomen that spreads to the left side and lower back. The person can describe the pain as a sensation boring that can be aggravated by eating, especially foods rich in fat.

The aneurysm aortic abdominal is another cause serious that may be the source of back pain that may be felt more on the left side. The aorta is the main artery of the body that extends from the heart to the lower part of the body. Your increase occurs when the arterial walls are weakened, which leads to an aneurysm-aortic.

In the majority of cases, it develops slowly without symptoms or only with symptoms insignificativos, as a discomfort around the stomach or a feeling of pounding in the abdomen. When an abdominal aortic aneurysm produces symptoms, pain and discomfort are usually severe and immediately visible.


Back pain, whether it is uniform or concentrated on one of the sides of the back, you can have multiple sources, so it is important that you register all of the defining characteristics of their pain to facilitate or guide the process of diagnosis. Identify the precise location of the pain, or if this spreads.

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It is also important to be aware of these and other questions: is this the first time it occurs? Improves/worsens with any posture? It is a constant pain and always with the same intensity? Increases when urinating/defecating? In the case of women, as if it involves pain during menstruation? There are other symptoms associated?