Common ragweed or Ambrosia artemisiifolia is a herb with lacy leaves. It is known by many names, such as hogweed, blackweed, Roman wormwood, stammerwort, hayfever weed, and wild tansy. The plant appears in late Spring, and its pollen can travel hundreds of miles via wind. The ragweed pollen is one of the most common causes of seasonal allergies as it develops an adverse immune response in many people. The immune system is programmed to detect harmful viruses and bacteria and defend itself against them. Despite many known health benefits of ragweed, the immune system can identify its pollens as invaders. This can cause allergic reactions in some people. Symptoms of allergic reactions to common ragweed allergen include: Itching sensation in the throat Watery and itchy eyes  Congestion and runny nose  Wheezing  Coughing  Facial pain due to sinus pressure  Poor quality of sleep  Swollen undereye skin with bluish colour  Reduced sense of taste or smell Exposure to the common ragweed allergen for too long may cause eczema in some patients. This is a painful version of the itchy rash, where bumps and blisters may appear on the skin after 24-48 hours. In most cases, the symptoms may go away on their own in two to three weeks. However, poor lifestyle choices and using substances like strong perfumes and tobacco can aggravate the condition. Even air pollution can make common ragweed allergies worse. Your doctor can diagnose the common ragweed allergy via the ragweed allergy IgE blood test. This test measures the specific count of the common ragweed allergen-specific IgE antibodies in the patient’s blood sample. Apollo 24|7 provides a comprehensive common ragweed allergy test, in which the lab technician visits you to collect the blood sample. The most common method of collecting it is by drawing blood from the vein of your arm using the venipuncture method. The testing is done with the Thermo Fisher ImmunoCAP or ImmunoCAP allergy testing method. The test results may take about three to six days to arrive or may take longer, depending on the weather. For most people, ragweed allergy may be a lifetime problem once developed. If you are diagnosed with a common ragweed allergy, you may have to consume the antihistamine tablets 12 weeks before the ragweed season every year. Your doctor may also prescribe nasal steroids, which are one of the best and most common treatments for this. For milder symptoms, doctors may prescribe an over-the-counter oral antihistamine.     Medically reviewed by Dr Jatin Ahuja, Infectious Diseases, Apollo Hospitals Indraprastha, South Delhi.