Degenerative Disc Disease: This is the most common cause of low back pain in older adults. The wear and tear on the spinal discs over time can lead to pain and stiffness in the lower back.

Lumbar Spondylosis: A condition characterized by the degeneration of the spine, including the discs, facet joints, and ligaments, which can cause low back pain.
Musculoskeletal Strain: Muscle strain or ligament sprain in the lower back can occur due to overuse, improper lifting, or sudden movements.
Herniated Disc: A condition where the soft inner gel of the disc leaks out through a tear in the outer layer, potentially irritating nearby nerves and causing pain.
Osteoarthritis: Wear and tear on the facet joints in the spine can lead to osteoarthritis, causing pain and stiffness in the lower back.

Cauda Equina Syndrome: A serious condition where the nerves in the spinal canal are compressed, leading to severe pain, numbness, and potentially permanent nerve damage if not promptly treated.
Spinal Infection (e.g., Discitis or Osteomyelitis): Infections of the spine can cause severe back pain and are medical emergencies.
Spinal Fracture: Especially in older adults with osteoporosis, a fracture in the spine can cause sudden onset of severe back pain.
Cancer with Metastasis to the Spine: Although less common, cancer that has spread to the spine can cause back pain and is critical to diagnose early.

Ankylosing Spondylitis: A form of arthritis that primarily affects the spine, although it typically starts at a younger age.
Spinal Stenosis: Narrowing of the spinal canal, which can put pressure on the spinal cord and nerves, causing pain and weakness.
Paget's Disease of the Bone: A condition that affects bone remodeling, leading to weakened bones and potential for deformities and pain.
Epidural Abscess: A rare but serious condition where an abscess forms outside the sac that contains the spinal fluid, which can compress the spinal cord and nerves.