A possible cause could be due to hypertension in the piriformis muscle.
The piriformis muscle is located in the hip region. The origin is at the sacrum and the insertion is at the greater trochanter on the head of the femur.
The piriformis muscle is functionally involved in external rotation, abduction, and partial extension of the hip.
Trigger points located in the piriformis muscle have a unique pain referral pattern. Pain is in the sacroiliac region and the posterior hip and thigh region. Pain can be increased through extended periods of sitting.
Homecare therapy options for the piriformis include:
Working out the trigger points with a lacrosse ball or foam roller
Maintain hip mobility by creating space. Keep moving.
Stretch out all surrounding muscles including glutes, anterior hip, and hamstrings.
If working at a desk continually, find a square seat/chair that is the right height and allows you to sit on the edge. Set a timer to remind you to get up from your chair every 30 minutes.
Of course, massage therapy is an effective way to help restore good tissue health. Manual manipulation increases blood flow, lymph drainage, and releases trigger points.