Low back pain
By Dr Amit Verma, MD (Anaesthesiology)
Low back pain (LBP) is one of most common reasons for a hospital visit amongst adults. It is also called lumbago. About 80% of the population needs medical advice for low back pain at some stage of their lives and in most of the cases, the painful episode subsides with simple measures.
What is the lower back and where does the pain originate?
Most of the lower back is made up of muscles that attach around the spine. The spine consists of multiple vertebrae piled up together at multiple joints with ligaments and muscles. All the vertebrae together form a cylindrical tube, inside which the spinal cord stays safe. Between the vertebrae is a soft intervertebral disc (IVD) or cushion, which acts as a shock absorber. The spinal cord, throughout its length, branches into 33 nerves which leave the canal through small foramen (openings).
Types of low back pain
Low back pain can arise from any of the structures mentioned above. It can be classified as
1. Simple or non-specific back pain
This is the most common type of back pain. It is called so because no underlying disease can be found. It may be because of a minor sprain of the ligaments or muscles, a minor problem with the small facet joints between the two vertebrae or a minor problem with the disc. It may be very difficult to exactly pinpoint the origin of the pain. The severity of the pain, however, may range from being very mild to very severe. The pain is usually located in one area of the lower back but may spread to the buttocks or the thighs. It may become worse with movement or be relieved by lying down. Most bouts ease off within a week or so, and 75 % ease up in about four weeks. But it is not uncommon to get a second bout of pain after some time.
2. Nerve root pain
This is caused by a nerve arising from the spinal cord being trapped or ‘pinched.’ The pain is usually felt along the course of the nerve. The pain might be felt running down the leg or the foot (eg sciatica). It worsens on bending, turning, coughing or sneezing and is relieved by lying down. It might be associated with numbness, tingling or weakness in a part of the buttock, leg or foot. The causes of the entrapment of a nerve include the swelling of a ligament, muscle or the more common slipped disc. In a slipped disc, the soft part of the intervertebral disc gets displaced into the spinal canal and presses on the nerve nearby.
3. Other causes of low back pain
Arthritis (inflammation of the joints) of the spine, especially in older people, sometimes causes back pain.
Ankylosing spondylitis is another cause occurring mainly in young adults and causes pain and stiffness.
Rheumatoid arthritis may cause LBA but it will affect the other joints too.
Spinal stenosis, which causes a narrowing of the spinal canal, may cause pain which increases on walking and gets relieved at rest.
What investigations are required?
Your doctor will normally be able to differentiate simple mechanical low backache or nerve root pain by taking a history and examining you. Tests such as an X-ray, and MRI may be required if you have warning signs of some serious underlying disease, or if the pain increases in severity and persists for months.
What is the treatment of low back pain?
Continuing with your daily routine and regular exercise is the best thing to do with a simple back pain. Pain relief medication can be taken after consulting your doctor. As a rule, don’t do anything that provokes pain. Rest might be required in the beginning but try returning to your normal activity as quickly as possible.
Interventions by your doctor can range from giving analgesics, physiotherapy, epidural steroid injections and surgery in cases that do not respond.
Surgical procedures like laminectomy and discectomy may be required in patients with nerve root pain.
What you should do when you have a low back pain…
Most cases of LBP subside on their own. Many people just ‘get on with it’ and treat it themselves. However, it is always good to see your doctor for a check up and advice.
As a general guide, if any of the following occur, it may indicate that it may not be a simple low back pain, and there may be a more serious underlying cause such as a nerve root problem, or another disorder. Therefore, see a doctor if you have any of the following:
– The pain first develops under the age of 20 years or over the age of 55 years
– Pain is severe enough to restrict your daily routine
– Constant back pain that is not eased by lying down or resting
– Pain travels to the chest
– If the pain develops gradually and slowly and gets worse over days or weeks.
In addition to back pain, the following are warning signs of a more serious underlying issue:
Weakness of any muscle in a leg or foot.
Problems with your bladder or bowel, such as not being able to pass urine or loss of control (incontinence)
Weight loss, fever, or if you feel generally unwell
Recent history of trauma or injury to the back
You have or have had a cancer of any part of the body
You have taken steroids for more than a few months
If you have a poor immune system. For example, if you are on chemotherapy or have HIV/AIDS