Chronic idiopathic urticaria (CIU) is a form of chronic hives that results in itchy, red bumps or wheals on a person’s skin. People with CIU usually have flares that come and go for several years, but doctors haven’t identified a direct cause.

Although there isn’t a clear underlying cause and symptoms can appear spontaneously at any time, you may notice that certain triggers can make your symptoms worse.

Below are some potential triggers that you should be aware of in order to better understand your condition.

Not all CIU triggers are physiological. They can also be psychological, stemming from stress or anxiety. Your mental state may play an important role in the manifestation of symptoms, so keeping your stress levels down can also keep your symptoms in check.

If you find yourself feeling anxious often, try some stress-relieving activities like meditation, breathing exercises, or yoga.

Although scratching your itchy skin offers temporary satisfaction, it may actually be a trigger.

Scratching can lead to a vicious cycle in which you become more aware of the itch and can’t stop yourself from focusing on it. This leads to even more scratching, and an even worse case of hives.

If you notice an onset of hives when you’re around certain animals, pet dander could be a trigger.

You don’t necessarily need to make direct contact with an animal for a reaction to occur. Flakes of skin can shed in places where an animal spends time, which could be enough to bring on a reaction.

Wash your clothes and clean your furniture often to prevent an allergic reaction from happening as much as possible.

Being outside during the summer can be a minefield for CIU triggers. Pollen, insect bites, and the sun’s heat can all lead to itchy bumps on your skin.

Don’t be surprised if spending time outdoors brings a sudden onset of hives. Apply bug spray and wear long-sleeved tops and pants to prevent insect bites. Consider wearing a hat to protect yourself from the sun.

On the other hand, the cold associated with winter (or cold conditions such as a swimming pool) can trigger a flare-up in some people. Ask your doctor to administer an ice cube test to see if a reaction occurs. If it’s discovered that cold is a trigger, your doctor will make appropriate recommendations, including protecting your skin in cold temperatures.

You may think that your runny nose and your hives are unrelated, but it’s possible that the two are connected. Anything from a viral respiratory infection to a dental infection can be a trigger. See your doctor to receive treatment for these as soon as possible so they don’t make your hives any worse.

Exercise, especially the vigorous kind that can cause you to sweat, may aggravate your CIU symptoms.

You don’t necessarily need to stop exercising altogether, but you may want to talk to your doctor about how to keep symptoms under control. They may recommend low-impact exercises such as cycling, swimming, or yoga. These exercises won’t make you sweat as much, but they’ll still get you moving.

The hormones related to your menstrual cycle may play a role in triggering hives. If you notice that flare-ups seem to occur around the same point in your cycle on a regular basis, it may be more than a coincidence. Bring this up to your doctor so they can recommend the proper treatment.

Extra pressure on your skin can lead to hives. This means that anything from a too-tight pair of jeans to an elasticized waistband to a belt buckled tightly might bring on symptoms.

Instead, try to choose loose and comfortable clothing that gives your skin room to breathe.

One of the best ways to understand the specific circumstances that exacerbate your CIU symptoms is to keep a journal tracking your symptoms. Note the dates of onset, the intensity of your symptoms, and any unusual activity around the time your symptoms start.

Reviewing your notes with a doctor may be able to help you identify patterns.

You may never be able to control your CIU symptoms completely, but understanding the factors that may play a role in bringing on an outbreak could help you avoid certain triggers.