A ragweed allergy is an allergy to the pollen of the ragweed plant, a common weed found in areas with disturbed ground all over the world. Around 75% of people with pollen allergies are allergic to ragweed, illustrating the pervasiveness of this allergy. While the allergy cannot be cured, steps can be taken to reduce its impact on the patient's life.

Ragweed starts releasing its pollen in midsummer, when warmth and mild humidity stimulate the plant to do so. The pollen is designed to be airborne, with each plant producing over 1,000 grains. For people with allergies, the airborne nature of ragweed pollen is a serious problem, because it can spread across huge distances, often ending up in areas where no ragweed blooms. When people inhale the pollen grains, they experience congestion, wheezing, coughing, eczema, and watery eyes.

Relatives of ragweed, including burweed marsh elder, mugwort, groundsel, eupatorium, rabbit brush, and sage, can also cause a ragweed allergy. Many people with allergies to ragweed also experience reactions to other pollens, and they may suffer from allergies from late spring until the fall, when frost and rain finally prevent the spread of pollens. Sensitivities to bananas, cantaloupe, and chamomile tea may also develop in individuals with a ragweed allergy.

People who suspect that they have allergies should consult an allergy specialist. The specialist can confirm the presence of allergies and perform skin sensitivity tests to determine which allergen is causing the problem.

Although this process can be time consuming and expensive, it is important, as otherwise it will be difficult to address the allergy.

After narrowing down the cause to ragweed, the doctor can also test for sensitivity to other pollens, along with relatives in the ragweed family, to give the patient a more complete picture of his or her condition.

There are several approaches to coping with a ragweed allergy. Because the pollen can spread anywhere, simply moving to an area without ragweed will not be effective. Instead, people should monitor pollen counts and air quality reports for their regions, avoiding outdoor activities on days with a high pollen count. Using air filtration in the home can also increase comfort, as can taking antihistamines to reduce the severity of allergic reactions. Some patients may opt to pursue immunotherapy, also known as “allergy shots,” a technique designed to reduce sensitivity to an allergen which can reduce the intensity and duration of a ragweed allergy.