Pain in the Sacrum and Below the Lower Back: Possible Causes

Lower back pain is very common. The sacrum is not always to blame: nearby are joints, ligaments, and nerves. Below is information about what is located in this area and what causes of pain occur.

Where the sacrum is located and what can hurt below the lower back

The sacrum is a large triangular bone made of five fused vertebrae. It lies between the lumbar and coccygeal vertebrae and connects the spine to the pelvis, forming the upper posterior part of the pelvic cavity. Above, the sacrum joins the fifth lumbar vertebra; below, it joins the coccyx; on the sides, it joins the pelvic bones.

On the anterior surface of the bone, on each side, there are four sacral foramina through which branches of the sacral nerves exit. Therefore, pain in the sacral area may come not from the bone itself but from a nerve.

The mechanics here are simple. The sacroiliac joints are hinges with a very small range of motion that bear a large load. When their mobility decreases, the hip joints and the joint between the fifth lumbar vertebra and the sacrum take over the work. The increased load eventually has consequences — from coxarthrosis to disc protrusion and herniation. Thus, pain in the sacrum turns out to be connected with neighboring structures.

Causes of pain in the sacrum

A common cause of back pain is injury, such as a muscle strain. Less common are conditions such as a displaced disc, sciatica (nerve compression), or ankylosing spondylitis. Very rarely, pain is a sign of a serious problem: fracture, tumor, infection.

The cause cannot always be identified precisely, and pain often resolves on its own. By course, acute pain is distinguished — sudden, lasting from several days to several weeks — and chronic pain if it persists for more than three months. Eight out of ten people experience back pain at least once in their lives.

Why it hurts below the lower back on the left and in women

The side of the pain by itself does not allow the cause to be identified.

In women, the causes of back pain are the same as in men. The sacrum in women is shorter, wider, and less curved than in men — this is a structural feature, not a disease.

What symptoms accompany pain in the sacral region

The nature of the sensations can vary — from dull and constant to sharp and sudden. The cause is indirectly indicated by what happens around the pain: it worsens with coughing, sneezing, or defecation, does not improve after rest, or is worse at night. There may be unintentional weight loss, swelling in the back area, or a change in its shape. If fever, chills, or general malaise are added to the pain, a conversation with a doctor is needed without delay.

How the cause of pain is determined: examination

Imaging methods are used for examination:

• radiographic assessment of the condition of the spine;
• discography — examination of the intervertebral disc;
• myelography;
• MRI.

The scope of examinations is determined by the doctor: they also decide which of them are needed in a specific case.

When to see a doctor

For a routine appointment: pain does not improve after several weeks of home management; it interferes with everyday activities; there is unexplained weight loss; swelling has appeared in the back area or its shape has changed; pain does not improve after rest or is worse at night; it worsens with coughing, sneezing, or defecation; it comes from the upper part of the back, between the shoulder blades.

Urgently: fever, chills, or general malaise together with pain; severe pain that began suddenly, or pain that is rapidly increasing.

Pain in the sacrum by itself is not a reason to call an ambulance. Call 103 or 112 if, together with it, the following have appeared: weakness, numbness, or tingling in both legs; loss of sensation in the genital and anal area; problems with urination or defecation, including incontinence; changes in sensation during sexual intercourse, problems with erection or orgasm; chest pain; pain began after a serious accident.

This material is for reference: it helps to navigate possible causes but does not replace a doctor's consultation.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer