My mother-in-law told her husband that she had a backache.

You should immediately express your concern and ask about the specific symptoms of discomfort. It is best to take her mother-in-law to the hospital for examination with her husband with her mother-in-law's consent. After all, low back pain may be a complication caused by many diseases, and only after examination and diagnosis can symptomatic treatment be carried out. Old people are generally not very uncomfortable, and generally do not mention it to their children. Since it must be serious, children must pay close attention to alleviating the physical and mental pain of the elderly and let them live a healthy life with quality.