1) Caused by a pinched nerve in the spine either by a disc or arthritis,
2) Caused by specific pathologies affecting the nerves themselves,
3) Caused by a metabolic process such as diabetes, other autoimmune disorders such as rheumatoid arthritis or vitamins/minerals deficiencies.
Most of these are usually affect the larger nerves (large fiber neuropathy) that can be evaluated by a test called Electromyography (EMG) and Nerve Conduction Velocity (NCV) testing. They are mostly (if not exclusively) by neurologist and Physical Medicine & Rehab Specialists.
Other types of neuropathies may only affect the smaller nerves (small nerve neuropathy) that can be detected by skin biopsies.
I hope this answers your question.
Back pain has so many reasons, from very benign such as muscle tension to malignant as cancer. The key factor is not to ignore it. However, most back pains are mechanical in origin, that means it may be coming from a simple sprain and strain of muscles and ligaments to arthritis in the spine and disc problems. Wrong posture can definitely contribute to this as well. Do you have pain radiation to the legs, to the groin region or buttocks? Do you have associated numbness or tingling in the legs? If so, then how far down they go for both pain and numbness? Any recent fever, chills, or weight loss? What are the alleviating and aggravating factors? Most of all, what age bracket are you in, male or female? Bottom line, you need to address this before further aggravation occurs. My suggestion is to seek advice from a physical medicine & rehab specialist.
Complete rest is not advised and as a matter of fact, will make it difficult to treat in a long run. Relative rest, use of epicondyle brace (sometimes) and avoiding extension motion of the wrist and fingers during the daily chores are recommended. Oral and topical anti-inflammatories are of help but on a short-term basis. You need to see a sports medicine physician to mostly guide your husband through a series of home exercises.