Lower back pain just above the buttocks can be caused by a variety of factors, including:

• Muscle strain: This is a common cause of lower back pain and can occur due to overuse, heavy lifting, or sudden movements. Muscle spasms can also cause short cramps and dehydration, leading to lower back pain.

• Sciatica: This condition occurs when the sciatic nerve, which runs from the lower back through the hips and buttocks and down each leg, is compressed or irritated. Sciatica can cause sharp or burning pain that radiates from the lower back into one buttock and down the leg.

• Sacroiliitis: This is an inflammation of the sacroiliac joints that connect the pelvis to the lower spine. Sacroiliitis can cause pain in the buttocks and lower back, which may worsen when standing for long periods, bearing more weight on one leg, or climbing stairs.

• Piriformis syndrome: This occurs when the piriformis muscle, which runs deep inside the buttocks and over the sciatic nerve, goes into spasm and puts pressure on the sciatic nerve. Piriformis syndrome can cause symptoms similar to sciatica.

• Other conditions: Other potential causes of lower back pain just above the buttocks include kidney stones or infections, ankylosing spondylitis, leg length discrepancy, and pregnancy.

If you are experiencing lower back pain just above the buttocks, it is important to speak to your doctor to determine the underlying cause and start appropriate treatment. Treatment options may include nonsteroidal anti-inflammatory drugs (NSAIDs), physical therapy, hot and cold packs, and avoiding prolonged sitting or standing.