Final answer:
The 1st line treatment for primary dysmenorrhea is the use of non-steroidal anti-inflammatory drugs (NSAIDs) to alleviate pain.
Step-by-step explanation:
The 1st line treatment for primary dysmenorrhea, which is severe period pain without any underlying medical conditions, usually involves using non-steroidal anti-inflammatory drugs (NSAIDs) to alleviate pain. NSAIDs, such as ibuprofen or naproxen, work by reducing prostaglandin production, which is responsible for the uterine contractions causing the pain. These medications can be bought over-the-counter and are effective in relieving menstrual cramps. It is important to follow the recommended dosage and precautions when using NSAIDs.