Disease is typically defined as a pathological condition in which a part of the body is not working properly or is affected in a negative way. Disease may be caused by a parasitic organism, a genetic defect, environmental toxins, poor lifestyle choices or the body attacking itself. The wearing out of the body is responsible for some diseases. Many diseases are felt to be due to a predisposition combined with a trigger factor. Several common signs warn of disease.
Pain
Pain is always an indication that something is wrong in the body. While it often a transient problem, recurrent pain may signal a disease. Chest pain may indicate coronary artery disease, a headache may indicate a brain tumor and joint pain may signal osteoarthritis.
Gastrointestinal illnesses may cause abdominal pain. Crohn's disease, colon cancer, stomach cancer, diverticulitis or a worm infestation may be responsible. MedlinePlus, a website maintained by the U.S. National Institutes of Health, explains that an inflamed appendix may also cause pain in the abdominal area.
Bleeding
Bleeding, other than menstrual bleeding or bleeding from an injury, is indicative of a health problem. A nosebleed may be due to an allergy, while a rectal bleed may be caused by colon cancer. Bleeding may also indicate a blood disorder.
Difficulty Breathing
Breathing difficulties may result from a wide variety of diseases. Respiratory illnesses such as asthma and emphysema may be responsible, but systemic problems such as severe anemia may also be the underlying cause. Shortness of breath may also be a sign of panic disorder, explains MayoClinic.com.
Memory Problems
Several diseases can cause memory problems. Alzheimer's disease is often the first consideration, but Parkinson's disease, Huntington's disease, syphilis or another disease may also be responsible.
Fainting
Fainting is often indicative of a serious underlying disease. Heart diseases and neurological diseases, such as seizure disorder, may cause an individual to faint. An infectious disease is sometimes responsible for fainting. According to the Merck Manual, fainting can also be the result of complications of Addison's disease, a hormonal disorder.
Skin Changes
A number of skin changes can be a warning sign of disease. A bluish hue to the skin may indicate a respiratory or cardiac disease, while reddened skin may be due to a neurological ailment. Skin that is easily bruised may signal cancer or a blood disorder. A change in a mole or the sudden growth of a new lesion may be due to skin cancer.
Fever
Fever is often an indication of disease. High fevers may be due to an infection, such as tuberculosis, while a low-grade fever may signal cancer or rheumatoid arthritis.
