Why might a patient experience side effects after taking a new medication?

A patient may experience side effects after taking a new medication primarily due to the body's reaction to the active ingredients in the medication or potential interactions with other medications. Each individual’s body can respond differently to medications based on various factors such as genetic makeup, existing health conditions, and other medications being taken concurrently.

The active ingredients within the medication can initiate pharmacological effects that can lead to unintended side effects. Additionally, if a patient is taking multiple medications, there is a risk of drug-drug interactions, which may amplify side effects or create new ones altogether.

While changes in diet, lack of exercise, and age can contribute to a patient's overall health and response to treatment, they are not the primary reasons for experiencing side effects from a specific medication. Therefore, the correct understanding of side effects is directly linked to how the body processes both the medicine itself and how it interacts with other substances.