The medical abbreviation "PRN" stands for "pro re nata", which is a Latin phrase that means "as needed". In medical settings, "prn" is often used to indicate that a medication should be given on an as-needed basis, rather than on a fixed schedule.
For example, a patient with a headache might be instructed to take a pain reliever "prn" for their headache, meaning they should take it as needed when the headache occurs. Similarly, a patient with high blood pressure might be instructed to take a medication "prn" if their blood pressure exceeds a certain threshold, rather than taking it on a fixed schedule.
It's important to follow the instructions for taking medications "prn" carefully, as overuse or misuse of these medications can have harmful side effects. Additionally, it's important to communicate with your healthcare provider about how often you are taking medications "prn", as this can help them determine whether adjustments to your treatment plan are necessary.