Oral contraceptives are prescribed for a client who smokes heavily. What side effect should the nurse warn the client might occur?

Oral contraceptives can increase the risk of thromboembolic events, particularly in individuals who smoke heavily. Smoking is a major risk factor that can amplify the likelihood of developing blood clots, especially when combined with estrogen-containing contraceptive methods. The hormones in oral contraceptives can contribute to hypercoagulability, which means the blood has a higher tendency to clot.

It's important for the nurse to educate the client about this risk and the potential severity of blood clots, including deep vein thrombosis and pulmonary embolism, which can have serious health consequences. Ensuring that the client understands this risk is crucial in promoting safe contraceptive use and encouraging discussions around smoking cessation strategies.

While headaches, weight gain, and nausea can also be side effects of oral contraceptives, they do not carry the same elevated risk associated with smoking. Hence, it is critical to highlight the risk of blood clots to clients who fit this profile.