How Decongestants Work Against Your Cold

Find relief for your cold and flu symptoms

Taking a decongestant can be a great way to treat cold and flu symptoms. A decongestant is a type of medication that helps clear up sinus and head congestion, providing much-needed relief. Although many people successfully treat their symptoms with decongestants, they might not always be the right choice for you.

What Are Decongestants?

Congestion in the nose, sinuses, and chest is caused by dilated blood vessels in the ​membranes in the nose and airways. When these membranes start to swell, you can feel it. Decongestants work by narrowing the blood vessels in the nose. They decrease swelling and inflammation, allowing more air to flow through and mucus to drain. Common types of decongestants include:

In addition to oral medication, decongestants also come in the form of nasal sprays and liquid medicine. Other medications, such as Tylenol Sinus, Advil Cold & Sinus, and Aleve Cold & Sinus contain decongestants in addition to pain relievers.

Decongestants are considered relatively effective for minor congestion from viruses and other illnesses. If your illness has become an infection, however, they probably will not work as well. You may need antibiotics to treat the infection before decongestants will work to clear the congestion.

Most decongestants are safe to use three to four times a day. Follow the advice of your doctor and read label instructions in order to ensure safe and accurate dosing. If you are using a decongestant nasal spray, do not use it for more than a week at a time. Using a nasal spray for too long can actually make congestion worse.

What Are the Side Effects of Decongestants?

Decongestants may provide mild side effects. Chemically speaking, decongestants are related to adrenaline, which is the natural decongestant, as well as a stimulant. In some cases, taking a pill or liquid decongestant leads to a jittery or nervous feeling, which can affect an individual's blood pressure, pulse and ability to fall asleep, though this is not common.

Some side effects of decongestants include:

  • Confusion
  • Feeling nervous
  • Headaches
  • Nausea or vomiting
  • Loss of appetite
  • Tremor
  • Restlessness
  • Dry mouth

More serious side effects that should be reported to your doctor immediately are:

  • Chest pain
  • Heart palpitations
  • Dizziness or fainting
  • Numbness or pain in hands or feet
  • Difficulty breathing
  • Hallucinations
  • Bloody diarrhea and abdominal pain
  • Seizures

Should Anyone Not Use Decongestants?

Most people can use decongestants safely, but they aren't for everyone. Do not administer decongestants to children under 6 years old. Talk to your child's doctor first before giving them to children between the ages of 6 and 12. You should always talk to your doctor about any medications you are currently taking and the possible interactions that can occur with introducing a decongestant (or any medication, for that matter), even if it is over-the-counter.

Do not take decongestants if you have any of the following:

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Article Sources

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  1. Treating acute sinusitis. [Internet]. Cologne, Germany: Institute for Quality and Efficiency in Health Care (IQWiG); 2009 Feb 9 Updated 2018 Oct 18. 

  2. Barshak MB, Durand ML. The role of infection and antibiotics in chronic rhinosinusitis. Laryngoscope Investig Otolaryngol. 2017;2(1):36–42. Published 2017 Jan 23. doi:10.1002/lio2.61

  3. Deckx L, De Sutter AI, Guo L, Mir NA, van Driel ML. Nasal decongestants in monotherapy for the common cold. Cochrane Database Syst Rev. 2016;10(10):CD009612. Published 2016 Oct 17. doi:10.1002/14651858.CD009612.pub2

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