Decongestants, such as pseudoephedrine and phenylephrine, can raise your blood pressure and heart rate. If you have high blood pressure, it's a good idea to check with your doctor or pharmacist to find out what's right for you. You can also try decongestant-free cold medicines, such as Coricidin HBP. For in-depth information, see WebMD's article on Decongestants and Antihistamines.