Health Issues - Health and Disease (GCSE Biology)

Health and Disease

In this section, we will look at health and disease from a general point of
view, looking at how we can define each term, and understanding the
general risk factors for both.

Health and Disease

Defining Health and Disease

Health is the state of well-being. It involves physical well-being, in terms of factors such as fitness, BMI, and lack of disease, and mental well being, in terms of factors such as stress, mental illness and psychology.

According to WHO (World Health Organisation), health can be formally defined as: ‘a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity’.

Disease is an example of poor health, often caused by presence of pathogens or foreign agents in the body. Health is therefore affected heavily by disease, but a lack of disease does not necessarily mean good health.

Factors Affecting Health and Disease

1. Viruses and Cancer

   • Viruses can increase risk of certain diseases. Some viruses can increase the risk of cancer. For example, infection by the human papilloma virus can lead to an increased risk of cervical cancer, and infection by the hepatitis virus could lead to a higher chance of suffering from liver cancer.
2. Immune System
   • Immunity affects disease and health. Those with a weakened immune system have a greater risk of suffering from diseases, as their bodies have weakened defences. HIV can weaken a patient’s immune system and leave them more susceptible to other diseases. Immune reactions to foreign substances can also lead to allergic reactions by the body. These can manifest as skin rashes and exacerbation of the symptoms of asthma.
   • Presence of a disease can lead to another. Some diseases can increase the likelihood of suffering from another disease. For example, as mentioned above HIV can weaken your immune system and make
     you susceptible to other diseases. Therefore, when infected by the tuberculosis bacteria, the immune system can’t fight it so HIV patients are more likely to suffer from tuberculosis with a more difficult recovery. Similarly HPV (Human Papillomavirus) is a virus that can affect your reproductive system but it can also make you more susceptible to developing cancers like cervical cancer.
3. Mental Health
   • Mental health can be affected by physical health. Severe physical health problems, such as disability, can impinge upon a person’s mental health. Similarly, mental health can lead to poor physical health – e.g. mental illness can lead to poor eating, which can lead to poor physical health in the form of obesity.