Lower back pain is a common problem in individuals of all ages. Most of the causes are benign that is related to an abnormal posture, excessive weight lifting, or as a part of systemic pain syndromes.
Since most of the causes are benign, majority of the patients respond to simple pain relief medicines and rest. However, lower back pain may also be caused by some medical conditions that need to be evaluated on an urgent basis.
Following are some of the important symptoms of lower back pain that needs an urgent evaluation and referral to the concerned specialist.
Lower back pain and leg weakness:
Leg weakness is an indicator of a neurological deficit. occasionally, the patient voluntarily restrains himself from movements because of the fear that the pain may worsen.
However, a neurological deficit is a serious problem. It may manifest as numbness, tingling, a shooting current like pain, and inability to move the leg.
Neurological deficit associated with leg pain may be caused by any condition that affects the spinal cord or the nerves that originate from it.
Some of the causes of leg weakness in a patient with lower back pain are as follows:
- Degenerative disc disease
- Disc prolapse or herniated vertebral disc
- vertebral collapse or fracture
- Spinal or paraspinal tumor
- Metastatic diseases
- Indolent infections and abscesses
- Guillain Barre syndrome
- Degenerative Disc disease:
- This condition mostly affects older individuals. Patients usually have a lower backache for a long time that worsens with movements and is relieved with rest.
- Specific postures might relieve or worsen the pain.
- Disc Prolapse or a herniated vertebral disc:
- Disc prolapse is the sudden protrusion of the intervertebral disc out of the intervertebral space that impinges on the surrounding nerves.
- Typically, the sciatic nerve is involved. Henceforth, the term sciatica is commonly used.
- Affected patients develop a sudden onset of shooting pain radiating from the back to the leg that may be associated with weakness.
- Disc prolapse usually follows after an individual lift a heavy object.
- Vertebral collapse or fracture:
- Compression fracture or vertebral collapse is usually a sequela of osteoporosis. However, other conditions leading to fragile bones may also result in vertebral collapse apart from trauma.
- These conditions include hyperparathyroidism, deficiency of vitamin D, chronic renal failure, sedentary lifestyle, use of corticosteroids, and cancers like multiple myeloma.
- Spinal or paraspinal tumor:
- Lower backache may also be caused by spinal or paraspinal tumors. Patients may notice progressive difficulty in walking, loss of bladder and bowel control, and impaired sensations in the legs.
- Spinal tumors include schwannomas, chordomas, and neurofibromas.
- Metastatic diseases:
- Sometime cancers may spread to the bones. Most cancers that spread to the bones include lung, breast, and prostate cancers.
- Patients have diffuse skeletal pains that are more marked in the axial skeleton.
- Metastasis to the bones may result in vertebral fractures leading to weakness.
- Indolent infections and abscesses:
- Chronic infections like tuberculosis may involve the spine leading to vertebral osteomyelitis. The surrounding structures like the nerves may also be involved resulting in weakness in the legs.
- Guillain Barre syndrome:
- This is an acute condition that manifests as weakness in the legs in the ascending pattern.
- Patients usually have a preceding diarrheal illness, followed by back pain, and weakness in the legs.
Lower back pain and fever:
When lower backache is associated with fever, it should always be investigated especially if the symptoms last more than 2 to 4 weeks.
Fever may be caused by infections or an inflammatory condition.
Acute infections that may result in backache include Dengue fever (Bone-breaking fever), infections of the kidneys, pelvic infections, and osteomyelitis of the vertebrae.
Chronic infections include brucellosis that may involve the sacroiliac joints and Tuberculosis that may involve the vertebrae or the psoas muscles.
Inflammatory conditions may also present with lower back pain and fever. Ankylosing spondylitis and other seronegative spondyloarthropathies primarily involve the spine and sacroiliac joints.
Lower back pain and early morning stiffness:
Stiffness and especially early morning stiffness is a symptom suggestive of an inflammatory condition.
Unlike the degenerative diseases like Osteoarthritis in which the pain worsen with movements, in inflammatory conditions, the pain improves with exercise and is worsens with rest.
Similarly, the pain is marked in cold weather and early in the morning.
So, lower backache with early morning stiffness may be seen in patients with ankylosing spondylitis, reactive arthritis, psoriatic arthritis, arthritis associated with inflammatory bowel diseases, and other inflammatory conditions of the back.
Lower backache and spinal deformity or Gibbus formation:
Gibbus deformity commonly involves the upper lumbar and lower thoracic vertebrae. It is commonly a sequela of spinal tuberculosis. Gibbus deformity is the visible protrusion of the collapsed vertebrae over the back that may or may not be painful to touch.
When the deformity is visible, it should never be ignored and urgent evaluation for spinal tuberculosis is important.
Other rare causes of Gibbus deformity is achondroplasia, mucopolysaccharidosis, and congenital hypothyroidism (cretinism)
Lower backache and urinary or bowel problems:
When patients with lower backache suddenly present with inability to urinate or have a loss of control over the bladder and the bowel, a spinal cord pathology must be suspected.
Patients may present with an inability to voluntarily urinate or may develop dribbling of the urine.
Since control over the bladder is lost, patients cannot sense the bladder even when it is overdistended. This results in urinary retention followed by continuous urinary dribbling.
Similarly, the patient may also present with severe constipation that may only be relieved with medications, enema, or manual stool removal.
Lower backache and weight loss:
Weight loss (unintentional weight loss) associated with a lower backache may occur in patients with serious conditions like cancers, chronic infections like tuberculosis, and severe malnutrition.
Patients who have a chronic diarrheal state, inflammatory bowel disease, alcoholics, and severely malnourished patients may develop vitamin D deficiency that may be associated with lower back pain and weight loss as well.