Bones are like any other part of the human body, they can be affected by disease. Human bone diseases may be hereditary, caused by infection, caused by a chemical imbalance in the body, or may be a form of cancer. There are also a number of bone, and bone related, diseases whose likelihood increases with age. This article will aim to give an overview of each category of disease, with an example of each.
A congenital disease is one a patient is born with and may have genetic cause. Thankfully congenital bone diseases are rare, but one of the most common is brittle bone disease or osteogenesis imperfecta. There are various forms, of varying severity, but in all cases the bones are abnormally weak and easily fracture. The disease is not curable and treatment typically consists of protecting the bones from excessive stress and strain. The bones of very young children may be broken simply by the act of picking them up, but the effect and the amount of fractures does diminish as adulthood is reached.
An imbalance in the body’s chemistry can affect any part of the body and bones are no exception. Known as biochemically caused bone diseases, it is the formation of bone and its regulation that are affected in such cases. Rickets was once a common disease caused by a poor diet deficient in vitamin D. Vitamin D plays an important role in the absorption of calcium from food and its redistribution via the blood to the bones. The bones weaken, and a common symptom is ‘bow legs’. The disease is now rare thanks to improved nutrition and can be treated with vitamin D supplements. Osteomalacia is a condition with similar symptoms to rickets, again giving rise to weakened bones. Here, however, calcium is poorly absorbed due to problems with the stomach. Problems with the kidneys can also lead to malabsorption of calcium and hence to similar bone problems.
Bones can also be infected by bacteria and the most well known condition is osteomyelitis. Bacteria can either enter the bone through the blood if the patient is infected elsewhere in the body, or through a deep cut, especially the kind where bone is exposed. Symptoms include pain and tenderness in the region of the bone, redness of the skin above the bone and increased feverishness as the infection develops. Today the condition can be controlled successfully with antibiotics, but is serious if not treated. Septicemia, or blood poisoning, is one of the more severe complications if treatment is delayed.
Bone tumors can be present and cause no problems at all. An abnormal lump, or exostosis, can form on almost any bone and remain for years. They may cause discomfort or hamper the movement of joints, but the main threat arise if they become cancerous. Then, in common with most cancers, the lumps grow rapidly and spread to other tissues. Pain and swelling are the main symptoms and early diagnosis is vital for successful treatment. Around two thirds of bone cancer patients can be fully cured and the disease is one of the most controllable of cancers for the remainder.
Of bone diseases that affect the elderly, osteoporosis is probably the best known. This is a decrease in bone density and again the strength of the bones is compromised, leading to them breaking more easily. The loss of bone density is a normal part of ageing but the affects can be alleviated by a good diet and regular exercise. Paget’s disease also affects the elderly predominantly and is a condition where bone is laid down abnormally resulting in thickening of the joints and associated pain. Osteoarthritis is strictly a disease causing loss of cartilage, but bones are affected as it is the cartilage which protects the bones forming a joint. Again it is a disease that becomes more common with age. It should be stated that the aim of this article is to give a general overview of bone diseases and it is not exhaustive.