Anyone who has experienced a severe allergic reaction is changed by the experience. It’s scary when a severe allergic reaction, such as anaphylaxis, is triggered. Even if you carry an epinephrine shot around with you, you probably hope that you’ll never actually have to use it.

In this article we’re taking a look at the real-life stories of people who have had a severe allergic reaction. They told us what happened as well as what they learned from the experience. These stories illustrate why it’s so important to always carry your epinephrine shot.

Tell Others about Your Allergies

The Allergy and Asthma Foundation of America (AAFA) recommends wearing a medical bracelet or necklace that lists your allergies. They also recommend carrying a card that explains your allergies. It is also advised that you tell family and friends about your condition and your triggers, along with what to do in an emergency.

Drew Aveling, the co-founder of OnlineAllergies.com, found out firsthand the importance of making others aware of your allergies after a frightening ordeal one Christmas:

“My stepsister was rushed to the hospital with a life threatening illness and was already in a coma by the time she reached the E.R.,” explains Aveling. “The first thing the doctors asked us was what drugs she was allergic to. We didn't know. We found out just in time that she was allergic to three of the five drugs being administered, which helped save her life.” The experience led Drew, who suffers from allergies himself, to start OnlineAllergies.com along with fellow allergy sufferer Jason Bierfeld. “It seemed crazy that we live in an age where we can transfer money to each other over our phones, but in times of real need we can't access basic life-saving allergy information of those we love most. So… we built a site that does exactly that. We got lucky, but no one should have to rely on luck to save a life.”

Sometimes It’s the Most Unlikely Trigger

In the case of John Nichol, a bus driver from Ontario, Canada, he experienced a severe allergic reaction to the last thing that you might expect: an allergy shot. An emergency shot of epinephrine came in handy at this time. He was at an appointment at his allergist’s office for his weekly allergy injections when he experienced a severe reaction to what was supposed to be one of his last injections.

“I was in the doctor’s office getting my allergy shot for environmental allergies when I had a reaction,” says Nichol. “I had the injection and went to the waiting room, as was standard for me, to wait for 15 minutes. I had just sat down when I felt my body go warm, then right to hot. They rushed me back into the exam room and called the doctor away from another patient. The doctor noticed that my breathing was getting raspy and quick, injected me with one of their Epi-Pens, and gave me some Benadryl. 911 was called and the Fire Department, paramedic, and an ambulance arrived. The paramedics took me to the hospital on oxygen and I was given multiple puffs of [albuterol] Ventolin.”

Although rare, severe reactions to allergy shots do happen. They are most likely to occur within 30 minutes of receiving the injection and require emergency treatment, according to the American Academy of Allergy, Asthma and Immunology (AAAI).

It Can Happen Even When You’re Doing Everything Right

The ACAAI lists knowing your triggers and avoiding them as the best ways to prevent an allergic reaction. Unfortunately, being diligent isn’t always enough. Sometimes you can encounter one of your triggers even when you’re doing everything you can to avoid them. This is a lesson that Toren Anderson, a branding consultant in Atlanta, learned the hard way.

“My first allergic reaction was from pine nuts in 1989 after a wedding,” says Anderson. “Since then I have experienced it five more times due to restaurant employees not telling the chef, and another time at the home of a friend that was unaware. The first time I ate an entire entree and it took over 30 minutes for the allergic reaction to kick in. By the time I got to the ER, my hands were navy and I did not recognize myself, even after being treated for hours. The second time, it was one tiny bite of a black bean sauce, and I almost didn't live through it.”

She also pointed out that when she suffered her most recent severe allergic reaction, she had told three waiters about her allergy, but the second course contained nuts nonetheless.

As these experiences make clear, carrying your epinephrine shot can save your life if you suffer from severe allergies. You can never fully predict when you’ll encounter one of your triggers.  If you experience severe allergies, be sure to talk to your doctor about on-the-go emergency treatment if you haven’t already.