Sitting hurts because stillness is the problem: hours in one position flatten your lower back's curve, raise pressure on the discs, and switch off the muscles that should be sharing the load.
The NHS names muscle strain as the most common cause of back pain, and says most backs improve within a few weeks with movement, not bed rest. Pymander is a free AI doctor, 24/7 by text, and can help you audit your setup.
What to do
Common questions
Why does my back hurt when I sit?
Your back is built for movement, and sitting still for hours asks it to hold one loaded position. When you sit, the natural curve of your lower back flattens, pressure through the spinal discs rises compared with standing, and the muscles that should share the load switch off - so joints, ligaments, and discs carry weight they are bad at carrying. The NHS lists a pulled muscle or strain as the most common cause of back pain, and hours of static slumped sitting is a reliable way to strain nothing in particular and everything a little. Sometimes medical conditions like a slipped disc or sciatica are behind it. The reassuring news from the NHS: back pain often improves on its own within a few weeks, and the treatment is movement, not rest - staying active beats bed rest, and specific exercises and stretches speed recovery. Practical fixes: stand or walk briefly every half hour, sit back so the chair supports your lower back with feet flat on the floor, and use a heat pack wrapped in a towel for stiff muscles. Anti-inflammatories like ibuprofen can help short term if they suit you. See a GP if it is not improving after a few weeks. Pymander is a free AI doctor, 24/7 by text, that can help you audit your setup.