What Does Being Healthy Mean?

Everyone wants to be healthy but what does that look like? In simple terms, you are healthy if your body is in homeostasis. So what does that mean? Think of this word as “stable home”. Your body is your “home”. In order to function properly, it must maintain stable conditions even though the outside environment may vary, such as cold, hot, or humid. Your doctor can check if you are not well by measuring certain internal conditions that are supposed to be stable. If they are out of whack, it means that something is wrong. For example, he or she may measure body temperature, blood pressure, heart rate, pH, and blood composition. If these numbers are out of the normal range you have a disease or disease condition. Therefore, the disease is a state in which the body lacks homeostasis.   

How Are Diseases Recognized?

The study of disease is called pathology and the physician who studies pathology is called a pathologist. Pathologists study the etiology (cause), mechanisms, signs, symptoms, treatment, and prevention of diseases. If the cause of the disease is not known, then the disease is said to be idiopathic

Diseases are recognized by their signs and symptoms. Signs are what the doctor sees or measures. For example, high blood pressure, high temperature, sweating, swelling, and rash. Symptoms are what the patient feels or experiences. For example, heat, pain, vomiting, frequent urination, and diarrhea. Some diseases are characterized by many signs and symptoms that occur together. Sometimes a disease may exist but the patient does not feel any symptoms. These diseases are hence referred to as asymptomatic. A collection of signs and symptoms is referred to as a syndrome. For example, Downs Syndrome and Acquired Immune Deficiency Syndrome (AIDS). 

What is a Diagnosis?

Collecting information on the signs and symptoms of a disease or disorder will give the doctor clues to help him decide which disease is affecting the patient. When he or she makes a determination on what disease the patient has, this is called a diagnosis. After making a diagnosis, the doctor may go on to give a prognosis for the disease. This is a prediction of what is expected for the patient such as chance for recovery and survival. Diseases that result in death is referred to as terminal. Some diseases revert to a period (days, months or years) where its signs and symptoms disappear even though the person is not healed of the disease. When this happens we say that the disease is in remission. On the other end, at certain times the signs and symptoms may worsen severely. We call this a period of exacerbation. Sometimes the patient may experience an improvement in signs and symptoms and then experience a time when the disease worsens. This worsening of the signs and symptoms is called a relapse. Some patients may develop other problems while they suffer from a disease. For example, a person suffering from diabetes may experience eye damage. This additional problem that occurs during the disease is called a complication

How Does the CDC Track Diseases?

Public health agencies such as the US Centers for Disease Control and Prevention (CDC) employ Epidemiologists to study and track the occurrence of diseases and gather statistics that can be used to tell us how widespread they are. By understanding how big the problem is, governments are able to prioritize the direction of resources towards their treatment, control, and prevention. Important statistics that agencies often report include the following:

  1. Mortality: How many people died of the disease
  2. Morbidity or Incidence: How many new cases of the disease are seen in a population e.g. the number of new cases of stroke patients per month 
  3. Prevalence: How widespread disease is in a population at a single point in time e.g. the percentage of adults over 55 y with Alzheimer’s disease at present
Epidemiologist Career Profile

What are the 9 Categories of Diseases?

The CDC provides valuable public epidemiological information on many diseases, including their causes. The causes of disease can generally be placed into one of these 9 categories:

  1. Hereditary: Diseases that run in the family e.g. sickle cell anemia 
  2. Congenital: Disease that is present from birth. It may be due to hereditary factors or development in the uterus e.g. Spina bifida 
  3. Degenerative: Diseases that do not get better but get worse over time e.g. Alzheimer’s disease 
  4. Neoplastic: Disease associated with the growth of tumor 
  5. Inflammatory: Diseases that result in inflammation due to an immune response. It is characterized by pain, heat, swelling, and redness e.g. inflammatory bowel disease and celiac disease 
  6. Metabolic: Disease that interferes with the body’s ability to absorb, extract, utilize or convert biomolecules from food to energy e.g. Type 2 diabetes 
  7. Trauma: Physical injury such as cuts and burns 
  8. Nutritional: Disease caused by eating too much or too little 
  9. Infectious: Diseases caused by pathogenic organisms e.g. Influenza  

What are the 5 Major Risk Factors for Disease?

The CDC also informs the public on risk factors for disease. These are factors that increase your chance of getting the disease. They are not the cause of them. Risk factors are generally placed in the following 5 categories: 

  1. Behavioral: e.g. smoking, drinking, food choices, exercise, unprotected sex, decision not to vaccinate 
  2. Physiological e.g. being overweight, high blood pressure, high blood cholesterol, high blood sugar
  3. Demographical e.g. age, gender, ethnic group, income, food security
  4. Environmental: e.g. access to clean water and sanitation, air pollution, workplace hazards
  5. Genetic: i.e. your chance of getting the disease is higher if someone in your family has it 

What are the Major Treatment Approaches Used by Doctors?

As we go through this spring semester of classes this year, I will share relevant information on diseases, with a focus on food and nutrition-related diseases, their causes, risk factors and finally, their treatment. Keep in mind that not all diseases are curable. Hence the approaches I discuss will depend on the specific disease. Treatment approaches may include:

  1. Use of drugs to cure diseases
  2. Use of drugs to relieve symptoms only (symptomatic treatment)
  3. Surgery to repair or remove damage
  4. Palliative care to provide comfort and relieve suffering only

Reference: Zelman, M., Raymond, J., Holdaway, P., Dafnis, E. & Mulvihill, M. L. (2015). Human diseases: A systematic approach (8th ed.). Boston: Pearson. 

Courtney Simons
Courtney Simons is a food science professor. He holds a BS degree in food science and a Ph.D. in cereal science from North Dakota State University.
Courtney Simons on EmailCourtney Simons on FacebookCourtney Simons on Linkedin