Normally, left-sided back pain emerges from common, day-to-day occurrences, like carrying heavy objects, having bad posture or doing repetitive movements. These can cause muscular damage or even compress the nerves. Mild injuries can be treated at home with rest and warm compresses.

However, back pain can also be a more serious situation, like kidney stones or a rib fracture, especially when the the pain is very intense or lasts for several days. In these cases, you should see a doctor to identify the underlying cause and initiate appropriate treatment.

The follow is a list of common causes of back pain on the left side and what to do in each case:

1. Muscular injury

Most back pain is muscular in origin, as the spine is the supportive frame for the whole body. This type of pain usually happens following physical activity, after completing physically-demanding tasks (like lifting and carrying heavy objects), or from poor posture. Even standing or sitting for too long can lead to a spinal injury and cause back pain. Pain can also be felt due to direct blows to the back.

Muscular pain usually worsens with movements. The pain is often described as heavy or tight, and can affect activities of daily living.

What to do: There are some ways to relieve muscle tension in the back at home. You can apply a warm compress to the affected region for 15 minutes twice a day, and apply an anti-inflammatory topical cream.

You should cease any strenuous activity while you are recovering so that symptoms can improve quickly. Interventions like acupuncture are proven to be effective in treating back pain. In the long run, you should pay attention to your posture throughout the day, and perform stretches to decrease muscular tension and relieve discomfort. Give these back stretches a try if your left-sided pain is located in the lower back.

2. Nerve compression

Nerve-related pain can trigger a very intense pain that can be shocking or stabbing in nature. One example of what can cause this type of pain is a herniated disc, which can compromise nerve roots that exit the medulla in the spine. Generally, this pain is felt in the middle of the back, but it can affect the left side as it radiates to the dorsal regions.

Another type of nerve compression that can cause back pain is sciatica, which involves inflammation of the sciatic nerve due to other back injuries (like a herniated disc), Symptoms of sciatica include tingling, sharp or shocking pain that radiates to the lower back and further along to a leg or foot. Older adults may experience sciatica due to age-related degeneration in the spine.

What to do: You are advised to apply a warm compress over the affected area and to avoid staying in the same position for prolonged periods. If the pain persists for a long time, you should see an orthopedic surgeon for an x-ray or MRI to identify the type of injury you may have. Treatment may involve the use of medication, physiotherapy and chiropractic therapy. You may find these stretches for sciatica helpful if your pain is sciatic nerve-related.

3. Kidney stones

Kidney stones, or renal calculi, are another trigger for back pain. This pain is usually strong and intense and may even prevent you from walking or moving. The pain usually does not resolve with rest or with changes in position, and can radiate to both sides of the back. If you suspect you have symptoms of kidney stones, complete our online quiz to assess your risk.

What to do: Kidney stones require treatment guided by a urologist or family doctor, who may prescribe analgesic and antispasmodic medication. If your pain does not improve or if it very intense, you should proceed to the emergency room to receive IV medications. Learn more about the treatment of kidney stones.

People with mild pain that are already on treatment for kidney stones should rest, ensure adequate hydration, monitor their food intake and take analgesics as prescribed.

4. Broken rib

If you notice pain on one side of the back that starts suddenly, or if the pain is very mild but persists for weeks and weakens that area, you may have a rib fracture. One of the classic symptoms of a broken rib is difficulty with breathing due to pain.

This type of fracture is more common in older adults due to weakening of the bones from small blows or normal degeneration. Athletes are also susceptible to this injury due to direct trauma, especially athletes who practice high impact sports, like wrestling or football.

What to do: If you suspect a rib fracture, you should see your doctor or go to the emergency room or testing, like a thorax x-ray. Imaging tests can confirm the injury and guide treatment, which usually involves the use of analgesics to relieve pain while recovering.

5. Infarct

Although it is rare, an infarct can cause left-sided back pain. Pain from an infarct usually starts in the chest and radiates to the left arm and shoulder. This type of pain is sharp, front, and can seem like a muscular injury that worsens with activity. Be sure you know the symptoms of a heart attack.

An infarct mainly affects older adults or people with a history of uncontrolled hypertension, cholesterol and diabetes.

What to do: If you suspect you may be having a heart attack, call 911 or have someone drive you to the emergency room immediately.

Other, less common causes

In addition to the above-listed problems, there are other causes of left-sided back pain that may be less common:

Bone cancer
Scoliosis
Inflammation of the lung lining
Osteoporosis

Because there are various causes for back pain, it is important to monitor for the characteristics of the pain, as this can help the doctor reach a diagnosis. You should be aware of how many times throughout the day you feel pain, if it is persistent or temporary, or if it worsens or improves with certain things, like taking a medication, changing positions, or urinating or defecating.

Back pain during pregnancy

Back pain during pregnancy is common and occurs due to the body’s adaptation to belly growth. The entire abdominal area is rearranged to make room for the baby, which can lead to muscular weakening and stress on the nerves of the spine. According to studies, pain is most felt in the lower back and more frequent in adolescent mothers. See how to relieve back pain during pregnancy.