Why Am I So Irritable? 16 Medical Causes of Irritability
Updated: Oct. 15, 2020
Feeling more irritable than usual? There could be a health condition, medical reason, or medication that's causing your irritability.
Why am I so irritable?
In times of uncertainty, it can be easy for emotions to fray and you may feel like you have a short fuse. Stressful situations, like the Covid-19 pandemic, the social justice movement, or political controversy, can trigger feelings of anger, fear, and anxiety, and that can also increase your risk of irritability.
But sometimes, feeling irritable may have nothing to do with life situations. Everything from a lack of sleep to certain medications could be to blame. So, the next time you ask yourself “why am I so irritable?” realize there may be medical reasons behind your bad mood.
We spoke with medical experts who reveal some surprising causes of irritability.
Lack of sleep
Make sleep a priority if you want to make sure your mood is as good as possible. Aim for seven to nine hours a night, rather than the five or six that many adults get. “Sleep is critical for proper mental health, so when you’re fatigued you get irritated,” says Steven Lamm, MD, clinical professor of medicine and medical director of the Preston Robert Tisch Center for Men’s Health at NYU Langone Medical Center. “It’s like a baby crying—you put them to sleep and they feel better. It’s the same thing.” Make sure you check out the other best ways to control your anger.
Dementia
When you start forgetting small things, like conversations or where you put your keys, it’s natural to become frustrated and snappish. However, you should only suspect dementia if there are other serious symptoms as well, not just irritability. “Generally I think of frustration as having to do with when needs don’t get satisfied,” says Jeffrey Deitz, MD, a psychiatry specialist with a private practice in Fairfield County, Connecticut. “Frustration can manifest with something that looks very much like irritability and outbursts to an outsider.”
Chronic pain
Pain that seems totally unrelated to mood, like a sore back, can make you crankier than usual while you’re dealing with the discomfort. “People don’t want to acknowledge that they’re in pain, so instead you see irritability,” says Dr. Lamm. “They’re not themselves and their temper is short because they’re in pain.” People display their irritability several ways. (Learn more about the types of anger to see which one you exhibit.)
Mild depressive symptoms
“There are many, many degrees of depression, from transient, which is part of normal human living, to clinical, which could severely impair someone’s life,” says Dr. Deitz. Low-level depression symptoms don’t get in the way of daily function like clinical depression, but they can make a person seem constantly grumpy and pessimistic, and they might be more likely to challenge you if you cross them, he says. Medication to manage clinical depression may exacerbate irritability, too. (Find out why low-grade depression is rising during coronavirus.)
Anxiety
Worrying about a deadline or upcoming event is enough to put anyone on edge, but people with anxiety disorders feel that way all the time. “When people are anxious, they are in a heightened state of arousal, and it takes less to make them jumpy,” says Dr. Deitz. “What might otherwise be somewhat irritating, in someone who’s anxious, they might react, or what you might call overreact, by screaming sharply.” (Pay attention to these anxiety disorder signs.)
Over-caffeination
“Caffeine is a chemical that has a powerful impact on the brain,” says Dr. Lamm. “Caffeine is an alerting agent, and when you withdraw from stimulation, you can be fatigued and irritable.” You might get cranky if you’re hooked on coffee but haven’t gotten your fix, or you could be on edge if you’ve downed too many cups of joe. Drinking more coffee makes you irritable and doesn’t make up for not getting enough sleep.
Heart failure
People with heart failure will be fatigued and might get preoccupied with their breathing, medication, and health—enough to put anyone on edge. Heart failure is a chronic condition where the heart becomes enlarged and has a hard time pumping enough blood to meet the body’s demands. It can cause shortness of breath, swelling of the feet, and other symptoms. Plus, heart problems mess with blood flow to the brain, which is what controls your emotions. “Anything that compromises blood circulation to the brain, especially the frontal lobes, can produce irritability,” says Dr. Deitz.
Premenstrual dysphoric disorder
A lot of women experience mood swings a couple of days before their periods, but if your premenstrual symptoms are severe, you could have premenstrual dysmorphic disorder, or PMDD, which is more intense. “Premenstrual syndrome is a perfect example of demonstrating how hormone variation results in mood swings,” says Dr. Lamm. “For some women, it’s so severe and long-lasting, it’s called premenstrual disorder syndrome when they’re really troubled by it.”
Perimenopause
Before some women start menopause, their hormones will begin fluctuating rapidly, leading to symptoms such as sleeplessness, hot flashes, and irritability. In fact, crankiness is one of the common signs of perimenopause to look for. “There’s a rapid and significant fluctuation in female hormones, mainly progesterone,” says Dr. Deitz. “That’s the irritability hormone in women.”
ADHD
A person with undiagnosed attention deficit hyperactivity disorder (ADHD) might start to snap if you get on their case about finishing tasks when they’re finding it impossible to focus. “People who have ADD are irritable because they can’t complete tasks, and they’re being asked to do more than they’re capable of doing,” says Dr. Lamm. But don’t be too quick to diagnose; bipolar disorder that’s mistakenly treated as ADHD can also cause snappiness because of how the medications react with the brain and nervous system, says Dr. Deitz.
Concussion
A head injury can cause a concussion, even if the person didn’t lose consciousness. In addition to lightheadedness and dizziness, watch out for a lasting mood change. “If you saw a change in personality and they became irritated ten days after a head injury and there’s nothing else to account for it, be really careful that they didn’t do something really bad to the brain,” says Dr. Deitz. “It’s emergent and persistent.”
Dieting
“As far as fluctuations in terms of mood, I’m always interested in what people are putting in their bodies,” says Dr. Dietz. One source he looks for? Certain over-the-counter diet remedies, which he says may “basically rev up the metabolism, but get people sweaty and anxious and prime them for outbursts.” Plus, not eating enough food can make you seriously cranky too. (Here’s why you get “hangry” when you want food.)
New prescription medications
Watch out for mood changes as a side effect of a new prescription. For instance, Dr. Deitz says prednisone, which is used to treat conditions such as allergies and asthma, is a major medication to keep an eye on. “High-dose prednisone is an example of a physiological stressor that can produce a lot of irritability,” he says. “You want to look for any changes.”
Hyperthyroidism
If your thyroid starts overproducing hormones, you could be left with a racing heart and excess sweating, making you revved up. “You’re just on edge,” says Dr. Lamm. “Whenever you just don’t feel well, that can lead to irritability.” However, eating may help alleviate your crankiness. (Try these proven mood-boosting foods.)
Narcissistic personality disorder
People with narcissistic personality disorder have a higher sense of self-importance than those without the mental disorder. They tend to talk about themselves a lot, and are likely to snap if they don’t get that same attention from others. “When they don’t get affirmation, or get criticized, boy do they go off,” says Dr. Deitz.
Substance abuse
People who abuse substances—particularly alcohol and cocaine—can get irritable during withdrawal. Alcohol pumps up dopamine levels in the “reward center” of the brain, so when those levels go back down and take the feel-good feelings with them, abusers could get cranky. “Alcohol itself may temporarily calm them for a little bit, but once alcohol levels fluctuate, they get irritable and need alcohol again,” says Dr. Lamm.
- Steven Lamm, MD, clinical professor of medicine and medical director of the Preston Robert Tisch Center for Men’s Health at NYU Langone Medical Center, New York City
- Jeffrey Deitz, MD, psychiatry specialist, Fairfield County, Connecticut
Medically reviewed by 
