Why is your foot numb all the time?
Persistent foot numbness is almost never a foot problem. In the vast majority of MRIs I review, the nerve that feeds that part of the foot is being squeezed in the low back, usually by a disc herniation crowding the small tunnel the nerve exits through. Take the pressure off the nerve and the numbness usually follows.
Listen, I look at low back MRIs every single day in our Walnut Creek office. And the pattern is so consistent it is almost boring. Someone comes in convinced there is something wrong with their foot. They have seen a podiatrist. They have new shoes, new orthotics, a new stretching routine. Meanwhile the actual problem is sitting four feet north of the foot, in a disc.
What is actually pressing on the nerve?
Two structures matter here. The spinal canal is the central highway that carries the whole bundle of nerves down your low back. The foramen is a small tunnel on each side of every level where one nerve peels off and heads down the leg. A disc herniation pushes into that tunnel and displaces the nerve that is trying to use it.
When I pull up a scan, I look at the healthy side first. Clean canal, open tunnel, nerve has room to breathe. Then I look at the other side and there it is: a large herniation sitting right on top of the exiting nerve. That is not a subtle finding. That is a car parked in a doorway.
Here is the same scan I walk patients through in the office:
Why won’t magnesium, stretching, or foam rolling fix the calf cramp?
Because the cramp is not coming from the calf. When the nerve that controls the calf muscle is compressed up at the spine, the signal going to that muscle is distorted, and the muscle misfires no matter how well hydrated you are. Magnesium, rolling, and stretching all treat a healthy muscle that is working too hard. They do nothing for a nerve that is being pinched.
I hear this every week. “I roll it out every night.” “I take magnesium before bed.” “I stretch my calf for ten minutes.” And the cramp is still there at 2 a.m. That is your body telling you the problem is upstream. Same story with the numbness in the foot, the tingling in the toes, and that weird patch on the outside of the shin that feels like it is asleep.
When is a numb foot an emergency?
Most of the time it is urgent but not an emergency. There are exceptions. Numbness spreading into the inner thighs or groin, new loss of bowel or bladder control, or rapid weakness such as a foot that starts slapping the ground when you walk all require same-day emergency evaluation, not a chiropractic appointment.
Everything else falls into the category of “do not wait six months.” Nerves tolerate compression for a while, then they stop tolerating it. The longer a nerve sits compressed, the longer the recovery tends to take once you finally take the pressure off. Time is the variable nobody thinks about until it costs them.
Can a disc herniation actually shrink without surgery?
Yes, and it can be measured on a follow-up MRI. In our first paper published in the Journal of Contemporary Chiropractic, four patients with lumbar disc herniations were treated with non-surgical spinal decompression plus chiropractic care over eight weeks. Post-treatment MRIs showed disc reductions of 9, 27, 30, and 78 percent, confirmed by independent radiologists, and all four patients were 100 percent pain-free without surgery.
Our second paper went after a harder case. A 50-year-old man with a C5-6 disc extrusion, upward migration of disc material, segmental instability, and cervical myelopathy with cord compression. That is the presentation that normally goes straight to a surgeon. After a three-month program his follow-up MRI showed a 52 percent reduction in the extrusion with no remaining cord compression, and he was still improving a year later. You can read both papers on our published research page.
The mechanism is not complicated. A decompression table creates negative pressure inside the disc, which draws herniated material back toward the center and pulls fluid and nutrients into a disc that has almost no blood supply of its own. If you want the longer version, here is how non-surgical spinal decompression works.
How long does it take for the numbness to go away?
It depends on how big the herniation is and how long the nerve has been compressed, but change can happen faster than most people expect. One of our patients flew into Walnut Creek from England with exactly this pattern: numb foot, calf cramp that would not release, and a large herniation sitting on the exiting nerve. In 18 days of care we reduced that disc by 30 percent, and she left pain-free and having avoided surgery.
That is not every case and I will not pretend it is. Some discs move in weeks and some take the full program. What is consistent is that the numbness starts to change once the nerve gets room, not before. That is why we chase the disc instead of chasing the symptom.
What should you do if your foot has been numb for weeks?
Three things, in order. Get an MRI if you do not already have one, because guessing at a nerve problem is how people lose months. Have someone actually walk you through the images and show you which nerve level matches your symptoms. Then find out whether that herniation is a candidate for non-surgical care before anyone books an operating room.
Half the people who come to see us have been told surgery is the only remaining option. Many of them never end up needing it. Before you commit to something permanent, it is worth knowing whether the reversible route was ever offered to you. That is the entire reason we built the avoid surgery side of this practice, and it is the same reason we treat sciatica and radiating leg pain at the disc level instead of at the leg.
Frequently asked questions
Can a herniated disc cause numbness in only one foot?
Yes, and one-sided numbness is the most common presentation. Each nerve exits through its own tunnel on its own side, so a herniation pressing into the left L5 foramen produces symptoms in the left leg and foot while the right side stays completely normal.
Does foot numbness from a disc herniation go away on its own?
Sometimes, and sometimes not. Smaller herniations can settle over months, but numbness that has been constant for weeks means the nerve is under sustained pressure, and waiting it out is a gamble with a nerve you only get one of.
Will magnesium help a calf cramp caused by a pinched nerve?
No. Magnesium can help a genuine electrolyte-driven cramp in a healthy muscle. It does nothing for a muscle that is cramping because the nerve controlling it is compressed at the spine.
Do I need an MRI before starting spinal decompression?
Yes. We do not treat a disc we have not seen. The MRI tells us the level, the size, the direction of the herniation, and whether decompression is appropriate for you at all. Bring the disc or the report to your consultation.
I don’t live near Walnut Creek. Can I still be treated at your clinic?
Yes. Patients regularly travel to our Walnut Creek center from across the Bay Area, out of state, and internationally, and we schedule out-of-town cases in condensed blocks so the travel is worth it. Send your MRI ahead of time and we will tell you honestly whether you are a candidate before you book a flight.
Get your MRI reviewed
If your foot has been numb for weeks and nobody has explained why, bring us your MRI. We will look at it with you and tell you what we see, including if we think you are not a good fit for what we do.
Contact our Walnut Creek office to get started.
Dr. JD Dudum, D.C.
Dudum Chiropractic, Walnut Creek