Health Management System - Deployment

Deployment

Such self-treatments according to evolutionary medicine are deployed to increase an individual’s biological fitness.

Two factors affect their deployment.

First, it is usually advantageous to deploy them on a precautionary basis. As a result, it will often turn out that they have been deployed apparently unnecessarily, though this has in fact been advantageous since in probabilistic terms they have provided an insurance against a potentially costly outcome. As Nesse notes: "Vomiting, for example, may cost only a few hundred calories and a few minutes, whereas not vomiting may result in a 5% chance of death" page 77.

Second, self-treatments are costly both in using energy, and also in their risk of damaging the body.

• Immunity – energy for activating lymphocyte and antibody production, and in the risk of an immune response resulting in an immune related disorder.
• Fever – energy (each 1 °C raise in blood temperature increases energy expenditure by 10–15%. 90% of the total cost of fighting pneumonia goes on increased body temperature. There is also the risk of hyperpyrexia.
• Sickness behavior – restricted ability by an animal to forage and defend itself
• Nausea – loss of food nutrients, and potential risk of aspiration
• Morning sickness – loss of food nutrients when a mother needs additional, not less, nourishment
• Hypoferremia – impairment in biological processes needing iron resulting in iron deficiency anemia
• Depression – impaired activity and problem solving.
• Pain – restricted movement and the inability to concentrate

One factor in deployment is low level physiological control by proinflammatory cytokines such as IL-1 triggered by bacterial lipopolysaccharides (LPS).

Another is higher level control in which the brain takes into account what it learns about circumstances and how that makes it well and ill. Conditioning shows the existence of such learnt control: give saccharin paired in a drink with a drug that creates immunosuppression, and later on, giving saccharin alone will produce immunosuppression. Such conditioning happens both in experimental rodents and humans.