Final answer:
Patients with heart disease or hypertension should be cautious about using decongestants because they can raise blood pressure.
Step-by-step explanation:
Patients with heart disease or hypertension need to be cautious about using decongestants because many decongestants contain sympathomimetic drugs like phenylephrine and pseudoephedrine. These drugs work by stimulating adrenergic receptors and can raise blood pressure. Since patients with heart disease or hypertension already have elevated blood pressure, using decongestants can further increase their blood pressure and put them at risk for complications. It is important for patients with these conditions to consult with their healthcare provider before using decongestants to ensure it is safe for them.