Medicine
Fact-checked

At TheHealthBoard, we're committed to delivering accurate, trustworthy information. Our expert-authored content is rigorously fact-checked and sourced from credible authorities. Discover how we uphold the highest standards in providing you with reliable knowledge.

Learn more...

What are Decongestants?

R. Anacan
R. Anacan

Decongestants are a type of medication that reduces congestion of the sinus and nasal passages. They are designed to ease the symptoms experienced when a person has a cold or is suffering from nasal allergies. Most decongestants are available for purchase over the counter (OTC); however some are only available with a prescription.

When the cold virus or an allergen is absorbed by the nose, the body produces a substance known as histamine. Histamine increases blood flow to the nasal area, causing blood vessels and the surrounding nasal tissue to swell up. This swelling inflames the nasal area, stimulating the production and leakage of mucus and excess fluid. The swollen membranes also limit the amount of space in the nose and nasal cavity where air can enter and exit, creating the feeling of stuffiness commonly associated with a cold or allergy.

Antihistamines help reduce the cause of the swelling of nasal tissues.
Antihistamines help reduce the cause of the swelling of nasal tissues.

Decongestants work by stimulating receptors in the sympathetic nervous system causing blood vessels and nasal tissue to shrink. This in turn helps reduce the body’s production of mucus and excess fluid. The reduced swelling leads to the nasal passages feeling more open and the symptoms of congestion being reduced.

Many decongestants are combined with a type of medication known as an antihistamine. An antihistamine counters the effect of histamine on the body. Therefore the antihistamine helps to reduce the cause of the swelling of nasal tissues, while the decongestant reduces the symptoms of nasal swelling.

Overuse of nasal sprays can cause the nasal passages to become dependent on the sprays to stay open.
Overuse of nasal sprays can cause the nasal passages to become dependent on the sprays to stay open.

Decongestants are generally made in two forms — oral and topical — both are equally effective. Oral decongestants are typically found in tablet, capsule, or liquid form. These usually take about 30 minutes to take effect and can be effective for up to 24 hours. It should be noted that an oral decongestant will cause blood vessels throughout the body to shrink, possibly raising an individual’s blood pressure. Those with high blood pressure or a history of heart disease should consult their health care provider before taking a decongestant.

Some decongestants may cause high blood pressure.
Some decongestants may cause high blood pressure.

Topical decongestants are generally found in drop or spray form and are applied directly to the user's eyes or nose. Topical medications start to work in approximately 10 minutes and can be effective for up to 12 hours. Users of topical decongestants, especially nasal spray, should not use it for more than two to three days, as prolonged use could lead to a rebound effect. When this occurs, the nasal passages are unable to remain open without the continued use of the nasal spray.

Discussion Comments

burcinc

@burcidi-- I'm not a doctor but I think that they do help with headaches because they constrict blood vessels. This is especially true if the headache is caused by congestion of the sinuses or nasal passages because these can cause headaches as well.

But if you want to take antihistamine decongestants for a regular headache (without congestion), I don't think that's a very good idea. It may be okay to do just once, but if you use it on a regular basis, you may become reliant on the medication.

Decongestants are habit forming, if you use it too often, you'll end up having to take it everyday. It's a kind of a vicious cycle where the more decongestants you take, the more chronic your symptoms become.

burcidi

Do decongestants help with headaches?

ddljohn

I used to take decongestants when I was young for colds. But I can't take them anymore because of high blood pressure. When I was first diagnosed with high BP, I took a decongestant cold medication not knowing that decongestants cause high blood pressure. My BP sky-rocketed that day and I went to the hospital because I thought I might have a heart attack.

Post your comments
Login:
Forgot password?
Register:
    • Antihistamines help reduce the cause of the swelling of nasal tissues.
      By: julaszka
      Antihistamines help reduce the cause of the swelling of nasal tissues.
    • Overuse of nasal sprays can cause the nasal passages to become dependent on the sprays to stay open.
      By: Kirill Kurashov
      Overuse of nasal sprays can cause the nasal passages to become dependent on the sprays to stay open.
    • Some decongestants may cause high blood pressure.
      By: WavebreakmediaMicro
      Some decongestants may cause high blood pressure.
    • People who have a history of hypertension should be cautious about using decongestants.
      By: Monkey Business
      People who have a history of hypertension should be cautious about using decongestants.
    • There are numerous decongestant medications available at drugstores.
      By: dusk
      There are numerous decongestant medications available at drugstores.
    • A doctor or pharmacist may recommend a combination of over the counter and home remedy treatments to overcome upper respiratory issues.
      By: Gennadiy Poznyakov
      A doctor or pharmacist may recommend a combination of over the counter and home remedy treatments to overcome upper respiratory issues.
    • Some decongestants come in the form of a nasal spray.
      By: oneblink1
      Some decongestants come in the form of a nasal spray.
    • Some decongestants may cause patients to experience dry eyes.
      By: Martinan
      Some decongestants may cause patients to experience dry eyes.