Your doctor will usually ask questions about your symptoms and examine you. The most common diagnosis is nonspecific low back pain and no tests are needed. In certain situations, tests such as X-rays, MRI, Electrodiagnosis (EMG, NCS) or blood tests may be advised.
Usually no investigation needed initially
Resting for 2 days lying on a firm surface could be optimal treatment
Longer than 3 days of rest have not additional benefit
Heat benefits some patients specially in the first 2–4 weeks of low back pain.