People can lose all or part of an arm or leg for a number of reasons. Common ones include
Some amputees have phantom pain, which is the feeling of pain in the missing limb. Other problems that can occur include grief, surgical complications and skin problems, if you wear an artificial limb. Many amputees use an artificial limb. Learning how to use it takes time. Physical therapy can help you adapt.
References and abstracts from MEDLINE/PubMed (National Library of Medicine)