What causes NUMBNESS or WEAKNESS in a foot or hand and why pain is a bad emergency signal

When a disc herniates, the disc nucleus can push outward through the disc wall and impinge and put pressure on a nearby nerve root that branches off from the spinal cord.

When that happens with a lumbar disc in the LOW BACK, the symptom might be pain that radiates into the flank or even pain that radiates into a foot. For a herniated disc in the NECK, the symptom might be pain that radiates into an arm, or even down into the hand. With the symptom of RADIATING PAIN, the person CAN USE WATCHFUL WAITING for a few weeks to see if non-surgical treatment options, like spinal injections, can provide relief without surgery. It will be very uncomfortable as the symptom of searing pain in a leg, foot, arm or hand can be extremely disabling. But radiating pain is not necessarily an emergency signal.

This is NOT the case with NUMBNESS or WEAKNESS in a foot or hand. This weakness can also be seen when the person is unable to lift the front of the foot when they walk. This is called FOOTDROP. These are all EMERGENCY SIGNALS that you need to see a spine surgeon within 48 hours, or this numbness or weakness could become permanent. The reason is that the disc is putting excessive pressure on the nerve root causing “neurological deficit”. If you don’t remove the pressure on the nerve root, it could be permanently damaged. Another emergency signal is LOSS OF CONTROL OF BOWEL OR BLADDER. Most people don’t associate this symptom with their back problem, but this can be an emergency signal where the disc has herniated and is compromising the area of the spinal cord that controls your bowel or bladder function. This symptom is extremely serious and you need to see a spine surgeon within 48 hours.

Again, YOU CANNOT USE WATCHFUL WAITING FOR NUMBNESS, WEAKNESS OR LOSS OF CONTROL OF BOWEL/BLADDER. You need to see a spine surgeon within 48 hours to prevent the symptom from becoming permanent.


Scott B. Phillips, MD is a neurological spine surgeon based in San Antonio who specializes in minimally invasive spine surgery, artificial disc replacement, carpal tunnel surgery, spinal cord stimulator implants and other brain disorders, including brain tumor and chiari decompression. Patients travel from Bexar County, San Marcos and South Texas, including Corpus Christi, Kingsville, McAllen and Brownsville for treatment of back pain, neck pain, brain tumor, carpal tunnel and epilepsy-related neurological problems. Dr. Scott Phillips provides a second opinion for back surgery and neck surgery, and emphasizes non-surgical treatment options in advance of spine surgery. Where surgery is necessary because of a herniated disc or spinal instability, Dr. Phillips uses minimally invasive spine surgery techniques and advanced technology like the artificial disc to help patients relieve pain symptoms and get back to activity. This spine neurosurgeon expertise enables many patients to have outpatient spine surgery and be home the same day. This educational web site at AlamoBrainandSpine.com has home remedies for back pain, neck pain and herniated disc. This site also has our philosophy of care about controversial treatments like laser spine surgery.