There are several things that can make sciatica worse.
Poor posture while sitting for long periods of time places pressure on the lower spine, increasing sciatica pain. Being overweight also places pressure on the lumbar spine (lower spine).
Other ways to make sciatica worse include:
lifting items with a posture that uses the back muscles instead of the legs;
doing exercises that put pressure on the lower back;
not getting enough exercise to keep the lower back muscles strong;
wearing shoes that shift body weight forward.
Twisting, coughing, or sneezing hard and straining can increase pain too. There is also ongoing medical research to determine whether emotional anxiety or stress play a role in the amount of pain felt with sciatica.