Why sciatica feels the way it does
Nicola Tik
Sciatica is one of those things that can feel completely out of proportion to what is happening in your body. A shooting sensation down your leg, a deep ache in the buttock, tingling in your foot. It can be hard to make sense of. This article explains what is actually going on and why the pain follows the path it does.
The sciatic nerve is the longest nerve in the body. It starts in your lower back, threads through the pelvis and buttock, and travels all the way down the back of the leg to the foot. Because of its length, anything that irritates it near the top can be felt a long way down.
The nerve does not generate the sensation on its own. When something puts pressure on it or irritates the area around it, often where it exits the lower spine or passes through the muscles in the buttock, your nervous system registers that as a signal and you feel it along the full length of the nerve.
This is called referred pain, and it is more common than many people realise. Your brain is not very good at pinpointing exactly where a nerve signal comes from. It simply knows that this particular nerve is involved and maps the sensation along the whole route. That is why you might feel relatively little in your lower back but a great deal of discomfort in your calf or foot.
The sensation can vary quite a bit depending on where the irritation is and how sensitive the nerve is at that moment. Some people describe it as burning, others as a dull ache, electric, or numb. All of these are different versions of the same thing.
In many cases, a disc in the lower spine is pressing against the nerve as it exits the spinal column. Discs are the cushioning pads between the vertebrae, your spinal bones, and they can bulge or shift position in ways that reduce the space available for nearby nerves. The lower lumbar discs are the ones most commonly involved.
In other cases, the irritation happens further along the route, often where the nerve passes close to a muscle in the buttock called the piriformis. Tightness or tension in this muscle can press on the nerve and produce similar sensations to those caused by a disc issue.
It is also worth knowing that nerve irritation does not always mean damage. A nerve that is compressed or sensitised can produce strong sensations without any lasting harm. Most episodes of sciatica settle with time and some gentle management.
When a nerve is irritated, certain positions stretch or compress it further, and others give it more space. That is why sitting for long periods can feel worse than walking, or why lying in a particular position brings relief. Your nervous system is responding to changes in load and tension along the nerve pathway. Understanding this can help you make small adjustments throughout the day rather than feeling stuck with the discomfort.
Sciatic pain often fluctuates, and this is normal. The nerve's sensitivity can change from day to day depending on activity, rest, stress, and even sleep quality. A day that feels manageable can be followed by a tougher one, without any clear reason. This does not mean things are getting worse. It usually reflects the natural variation in how a sensitised nerve responds to the demands of daily life.
Your VIDA pain check-in is a good way to keep track of how things are shifting over time, especially if you want to spot patterns in what seems to help or what tends to aggravate things.
If you develop any weakness in your leg or foot alongside the pain, or if your symptoms are getting progressively worse rather than fluctuating, it is worth speaking to your GP.