Often, the most debilitating lower back pain, for both men and women, is the type that comes on suddenly, leaving you in significant pain with limited mobility. The severity of the pain and the suddenness can be alarming—but it’s very common. In the vast majority of cases, this back pain is not related to a serious disease or severe back problem, but could be due to something simple like muscle spasm or another musculoskeletal cause. When the exact origin of back pain isn’t clear, it’s referred to as nonspecific low back pain. This “mechanical” back pain is generally eased by lying down flat and made worse when you move your back, sneeze or cough.