Possible Causes of Mood Swings

Two faces reflection

 electravk / Getty Images

In This Article
Table of Contents

"Mood swings" is a common term used to describe rapid and intensely fluctuating emotions. People often describe mood swings as a “roller coaster” of feelings from happiness and contentment to anger, irritability, and even depression.

A person may recognize something that has “triggered” a shift in their mood, such as a stressful event at work. But it’s also not uncommon for mood swings to occur without an obvious cause. People may experience these changes in mood over the course of a day or even within a couple of hours.

For example, your grumpy coworker might say they “woke up on the wrong side of the bed” when they arrive at the office feeling irritable. When you see them later in the day, their mood may have improved. In fact, they may not even recall why they were in a bad mood before.


Everyone experiences mood swings from time to time, but if you seem to get them frequently or they are so intense that they disrupt your daily life (including work and relationships), it may be a sign of an underlying condition that needs treatment.

Internal changes that take place throughout our lives influence our mood, but it’s not just what’s happening inside that determines how we feel; we also respond to what’s happening around us. External changes to our lives and in our environments, such as increased stress at home, school, or work, can also influence our emotions.

Illness and Injury

Even though the term “mood swings” implies an emotional root, the shifts can also be associated with chronic diseases or acute injuries that affect the brain, such as dementia, concussion, or a stroke. Other medical conditions (particularly neurological conditions) can also cause mood swings, including:

  • Diabetes
  • Sleep disorders
  • Multiple sclerosis
  • Thyroid disorders
  • Parkinson's disease


Toddlers and young children often appear "moody" and may throw tantrums as they learn to regulate their emotions. While they're generally a normal part of emotional development, mood swings in children can also be a sign of an underlying mental health disorder, learning disability, or even a physical ailment.

For example, kids and teens with attention deficit hyperactivity disorder (ADHD) may experience shifts in mood that can interfere with school and friendships.

As kids get older, mood swings continue to be a normal part of their development. By the time they enter the preteen years, fluctuations in mood are primarily driven by hormonal changes. These shifts in mood tend to peak during adolescence and gradually stabilize by young adulthood. 


A person who is eating a diet that's nutritionally inadequate or not getting enough to eat may experience mood changes in response to fluctuating blood sugar levels and malnourishment. For example, if you notice your grouchy coworker has more spring in their step after they have breakfast and a cup of coffee, their bad morning mood may have been stemming from caffeine withdrawal or low blood sugar (hypoglycemia). 

Digestive disorders that affect the body's ability to absorb nutrients, such as Celiac disease and inflammatory bowel disease (IBD), have also been associated with mood swings. These conditions have also be linked to specific mental health conditions, such as depression.


If you have seasonal allergies, you may find that your mood is influenced by the time of year you tend to have symptoms. Constant sneezing, watery eyes, and itchiness can also lead to fatigue, especially if they interfere with sleep.


A person’s mood can also be heavily influenced by the amount and quality of sleep they get. A person who is sleep-deprived (especially when chronic) may experience intense mood fluctuations as well as other psychiatric symptoms.

Maybe your colleague just isn't much of a morning person, but their mood naturally lifts as they wake up and they feel more prepared for the day ahead. The body’s circadian rhythm, which is known for influencing when we sleep, also drives our mood throughout the day to a certain extent. 


Starting or stopping a prescription medication can also affect a person’s mood. While medications such as antidepressants and mood stabilizers are expected to affect a person's moods, medications prescribed for other reasons may also cause mood swings as a side effect.

Even though mood changes can be a symptom of depression or another mental health condition, some medications used to treat these disorders can also cause changes in mood.

Sometimes, these mood shifts indicate that the medication isn’t the right choice for treatment, or that the diagnosis someone has been given may not be correct. For example, a person who has bipolar disorder may be misdiagnosed with depression and prescribed medication.

However, certain antidepressants may trigger a manic episode in someone with bipolar disorder. People who take anabolic steroids can experience intense mood changes including rage.

Substance Use

People who are dealing with substance use disorders may also be more prone to experiencing extreme shifts in mood, especially when they are unable to get or use a substance, or when they are trying to quit a drug and experiencing withdrawal. When misused, medications known to cause mood changes can have especially severe effects. For example, symptoms may be erratic and even life-threatening if a person (such as an athlete) misuses steroid medications. 

If mood swings come on suddenly, are highly irrational, or become suicidal, seek immediate medical care. 


Other possible causes of mood swings may stem from an imbalance of the brain chemicals that are associated with mood regulation, as in the case of bipolar disorder

Fluctuations in brain chemicals can also be a normal function, such as the hormonal changes of the menstrual cycle. For the same reason, mood swings are also common in response to other causes of shifting levels of hormones (especially estrogen), such as pregnancy and menopause.

However, a person’s risk for depression is increased during these times as well, so mood swings can also be a sign of a mental health condition.

Certain forms of hormonal birth control, such as the Pill, may help ease mood swings associated with the menstrual cycle, but it’s also been suggested that changes in mood could be a side effect of these medications. However, more research is needed, as other studies did not find a link between oral contraceptives and mood swings. 

Mood Swings and Mental Illness

While shifts in mood can be completely normal, triggered by stress, and/or part of dealing with a physical health condition, mood swings can also be a symptom of mental illness. 

When characterizing and diagnosing mental health disorders (particularly bipolar disorder and borderline personality disorder), the constellation of intense, rapid, and frequent shifts in mood is sometimes referred to as “emotional lability.” 

However, a labile mood is not unique to mental illness. It’s also seen in people with traumatic brain injury, stroke, and Alzheimer’s, as well as other medical conditions. 

If you are experiencing changes in mood along with other specific signs and symptoms of a mental health condition, talk to your doctor. Understanding the underlying cause is essential to finding the most effective way to manage your mood swings. 


Mood swings are also common with depression (especially if it is untreated). A person’s mood may fluctuate from irritability to extreme sadness to an angry outburst. People who are depressed may also have other symptoms, such as:

  • Feeling sad, hopeless, and worthless
  • Have trouble sleeping or sleeping too much
  • Eating more than usual or not eating enough
  • Feeling exhausted, tired, and fatigued
  • No longer enjoying favorite activities
  • Difficulty concentrating and/or making decisions
  • Having thoughts of death or suicide

Similar to depression and sometimes thought of as a “milder” form of bipolar disorder, cyclothymia is a condition characterized by periods of low mood that alternate with hypomania.

Bipolar Disorder

Mood swings are a hallmark symptom of bipolar disorder. There are two main types of bipolar disorder: bipolar I and bipolar II. Both are characterized by periods of mania or hypomania that alternate with depression. Some people experience both sets of symptoms at the same time (known as mixed episodes). 

The mood swings for people with bipolar disorder may contain some or all of the symptoms of a depressive or manic/hypomanic episode. A person experiencing an episode of mania may:

  • Talk a lot/very fast
  • Have excess energy 
  • Engage in risky behavior
  • Appear “on edge” or irritable
  • Feel like sleeping less than they normally do (but don’t feel the need for more sleep) 
  • Be more active or goal-oriented than usual (e.g., taking on new projects, working more/harder, starting new hobbies)

During a period of depression, a person with bipolar disorder may: 

  • Feel worthless or hopeless
  • Seem sad, cry often, or be tearful
  • Have no energy, feel exhausted or “wiped out”
  • Feel like they can’t focus or concentrate or thoughts/tasks
  • Stop feeling like doing things they used to enjoy
  • Sleep more than usual OR be unable to fall/stay asleep
  • Eat more or less than they usually do (weight loss or gain)
  • Have thoughts of dying or death; planning/attempting suicide

If you are having suicidal thoughts, contact the National Suicide Prevention Lifeline at 1-800-273-8255 for support and assistance from a trained counselor. If you or a loved one are in immediate danger, call 911. 

For more mental health resources, see our National Helpline Database.

How long it takes for the episodes to change a person’s mood to shift to the other end of the spectrum can vary from person to person. People who have “rapid-cycling” symptoms may experience shifts daily or weekly, while others may stay in one type of episode for months or years.

Medications used to treat bipolar disorder may help manage these intense shifts. Of note, researchers are getting better at predicting the mood shifts in people with bipolar disorder, which may help doctors diagnose and treat the condition. 

Borderline Personality Disorder

Borderline personality disorder (BPD) is another mental health disorder that can cause persistent mood swings. These mood shifts are typically intense and variable and can last from a few hours to a few days. Other symptoms of BPD include:

  • Impulsive and risky behavior (such as unprotected sex, reckless driving, substance use)
  • Extreme reactions such as rage or panic to abandonment (real or imagined)
  • Feeling empty or restless
  • Self-harming, threatening or attempting suicide
  • Emotional and intense relationships with others
  • Anger issues (outbursts, inappropriate anger, inability to control temper)
  • Dissociative symptoms (loss of time, feeling "outside" one's own body)


Mood swings can be challenging to deal with, especially if they interfere with your day-to-day life, school or work, and your relationships. Changes in mood that are frequent and intense should be discussed with your doctor, as you will need to figure out the underlying medical and/or mental health cause before you can effectively treat them.

Medications called mood stabilizers, psychotherapy or counseling, and interventions such as cognitive-behavioral therapy (CBT) may be helpful if an underlying mental illness is causing mood swings or making them worse.

You may be able to manage less frequent, mild, or occasional mood swings on your own, especially if you have a good sense of what “triggers” them. The first step is identifying factors in your life and environment, such as stress, poor sleep, or skipping your morning coffee, that precede or cause your mood swings. 

To better manage and cope with these changes in mood, you may want to experiment with different approaches, such as:

  • Getting regular exercise
  • Making changes to your diet
  • Learning stress management techniques
  • Adjusting your nightly routine to improve sleep

A Word From Verywell

While some degree of variation in mood is just a part of life, they shouldn’t interfere with the quality of your life. If your mood swings don’t improve or get worse, be sure to let your doctor know. 

Was this page helpful?
Article Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Balbuena L, Bowen R, Baetz M, Marwaha S. Mood instability and irritability as core symptoms of major depression: An exploration using Rasch Analysis. Front Psychiatry. 2016;7:174. doi:10.3389/fpsyt.2016.00174

  2. Angst J, Dobler-Mikola A. The Zurich study: II. The continuum from normal to pathological depressive mood swingsArchiv für Psychiatrie und Nervenkrankheiten. 1984;234(1):21-29.

  3. Kendler KS, Eaves LJ, Loken EK, et al. The impact of environmental experiences on symptoms of anxiety and depression across the life span. Psychol Sci. 2011;22(10):1343-52. doi:10.1177/0956797611417255

  4. Broome MR, Saunders KE, Harrison PJ, Marwaha S. Mood instability: Significance, definition and measurement. Br J Psychiatry. 2015;207(4):283-5. doi:10.1192/bjp.bp.114.158543

  5. Penckofer S, Quinn L, Byrn M, Ferrans C, Miller M, Strange P. Does glycemic variability impact mood and quality of life? Diabetes Technol Ther. 2012;14(4):303-10. doi:10.1089/dia.2011.0191

  6. Bathla M, Singh M, Relan P. Prevalence of anxiety and depressive symptoms among patients with hypothyroidism. Indian J Endocrinol Metab. 2016;20(4):468-74. doi:10.4103/2230-8210.183476

  7. Sobanski E, Banaschewski T, Asherson P, et al. Emotional lability in children and adolescents with attention deficit/hyperactivity disorder (ADHD): Clinical correlates and familial prevalence. J Child Psychol Psychiatry. 2010;51(8):915-23. doi:10.1111/j.1469-7610.2010.02217.x

  8. Cservenka A, Stroup ML, Etkin A, Nagel BJ. The effects of age, sex, and hormones on emotional conflict-related brain response during adolescence. Brain Cogn. 2015;99:135-50. doi:10.1016/j.bandc.2015.06.002

  9. Busby E, Bold J, Fellows L, Rostami K. Mood Disorders and gluten: It's not Aal in your mind! A systematic review with meta-analysis. Nutrients. 2018;10(11):1708. doi:10.3390/nu10111708

  10. Saghir Z, Syeda JN, Muhammad AS, Balla Abdalla TH. The amygdala, sleep debt, sleep deprivation, and the emotion of anger: A possible connection? Cureus. 2018;10(7):e2912. doi:10.7759/cureus.2912

  11. Cartwright C, Gibson K, Read J, Cowan O, Dehar T. Long-term antidepressant use: Patient perspectives of benefits and adverse effects. Patient Prefer Adherence. 2016;10:1401-7. doi:10.2147/PPA.S110632

  12. Gitlin MJ. Antidepressants in bipolar depression: an enduring controversy. Int J Bipolar Disord. 2018;6(1):25. doi:10.1186/s40345-018-0133-9

  13. The influence of estrogen on female mood changes. Chin Sci Bull. 2012;57:1351. doi:10.1007/s11434-011-9936-0

  14. Schaffir J, Worly BL, Gur TL. Combined hormonal contraception and its effects on mood: A critical review. Eur J Contracept Reprod Health Care. 2016;21(5):347-55. doi:10.1080/13625187.2016.1217327

  15. Kulacaoglu F, Kose S. Borderline personality disorder (BPD): In the midst of vulnerability, chaos, and awe. Brain Sci. 2018;8(11):201. doi:10.3390/brainsci8110201

  16. Bowen R, Peters E, Marwaha S, Baetz M, Balbuena L. Moods in clinical depression are more unstable than severe normal sadness. Front Psychiatry. 2017;8:56. doi:10.3389/fpsyt.2017.00056

  17. Culpepper L. The diagnosis and treatment of bipolar disorder: Decision-making in primary care. Prim Care Companion CNS Disord. 2014;16(3). doi:10.4088/PCC.13r01609

  18. Biskin RS, Paris J. Diagnosing borderline personality disorder. CMAJ. 2012;184(16):1789-94. doi:10.1503/cmaj.090618

Additional Reading