Hello dear, Though symptomatic relief from pain can be obtained with analgesics, the underlying cause needs to be treated. Considering the fact that your back becomes stiff and pain aggravates on lying down, the symptoms can be attributed to para-spinal spasm and entrapment of nerve fibers at the lower spinal region. Other causes can be: 1. Inadequate hydration status & electrolyte imbalance of the body. 2. Dietary deficiencies of certain nutrients like Iron, Calcium, Vitamin D, Vitamin B12, Folic acid, etc. which help in blood formation & nerve conduction. 3. Peripheral neuropathy caused due to any fluctuation in blood pressure or blood sugar level. Symptomatic relief can be obtained by intake of nervigenic agents (like Vitamin B6, Vitamin B12, Folic acid) as well as multivitamin & multimineral supplements including iron, calcium & Vitamin D needs to be added in your diet. Physiotherapy & postural exercise will also be helpful. If symptoms still persist, kindly consult a Neurologist & get a complete Neurological examination done. Certain investigations like complete blood count, serum electrolyte estimation, fresh estimation of blood pressure & blood sugar levels & nerve conduction studies will be helpful to rule out any pathological cause for the symptoms. X ray & MRI of lumbosacral spine can also be carried out to detect any nerve entrapment. Wishing you a Good Health. Take care.