You didn’t think you’d have a problem helping your high school buddy move out of his apartment. Sure, that sofa was heavy, but it was only two flights of stairs. Now, the pain shooting down the back of your right leg is making you think otherwise.

You may have a type of back condition called sciatica, an irritation of a nerve that runs down your leg. Our bodies have nerves that branch out from the lower back through the hips and buttocks down both legs. The pain can happen anywhere along the path of the nerve—which can make it difficult to diagnose.

Sciatica commonly occurs when a herniated or degenerative disk, bone spur on the spine, or narrowing of the spinal canal (spinal stenosis) compresses part of a nerve—resulting in inflammation, pain, and numbness.

These conditions can be caused by:

• Overuse of your back, such as lifting something that is too heavy
• An injury from a fall, or having something hit your back
• Excess body weight increases stress on the spine, which can contribute to bone spurs and herniated disks
• A sedentary lifestyle or a job that forces you to sit for long hours
• Always keeping an item in your back pocket, like a thick wallet, when you sit
• Diabetes, which increases the risk of nerve damage

If you’ve ever experienced a flare-up of sciatica, you know it differs from other types of back pain. Instead of a throbbing in one place, it can range from a mild ache to a sharp, shooting pain, or a burning sensation to an electric shock. Aside from pain, some people develop numbness, tingling, or weakness in a leg or foot, or multiple symptoms in different parts of the leg. Typically, though, people only experience symptoms on one side of their body.

Seek immediate medical treatment if you experience:

• Sudden, severe pain in your lower back or leg, and numbness or muscle weakness
• Pain following an injury, such as a traffic accident or sports incident
• Trouble controlling your bowels or bladder, or numbness in that area

The good news is that mild sciatica usually dissipates over time with conservative management such as pain relievers, alternating heat and ice, avoiding lifting or bending, and physical therapy.

Consult your primary care physician if your pain lasts more than a week or two, or becomes severe or progressively worse.

To reduce your chances of flare-ups, I recommend:

• Lose weight if you are overweight.
• Do warm-up stretches before participating in activities.
• Do regular aerobic exercises to strengthen your back and abdominal muscles.
• Lift properly, bending your knees and hips and keeping your back straight.
• Practice good posture.