Mood swings can happen due to a variety of factors, including stress, hormonal changes, mood disorders, or related mental health conditions.
Stress or Stressful Life Events
Certain stages or times during your life may be more stressful than others, which may make you more prone to mood swings, says Dr. Gardenswartz. For example, going through a divorce or breakup, getting laid off, or grieving the loss of a loved one could all lead to a variety of challenging emotional changes, including mood swings.
We all go through hormonal changes at different periods of our lives, which can cause mood swings.
Hormonal changes that happen to children as they enter their preteen and teen years commonly lead to mood swings. Mood swings during adolescence that are associated with puberty are a normal part of development and are usually temporary, notes Gardenswartz.
For women, hormones also tend to fluctuate during the menstrual cycle, pregnancy, and menopause, which may lead to mood swings. Premenstrual syndrome (PMS) and premenstrual dysphoric disorder, which is a more severe form of PMS, can cause mood swings during the menstrual cycle, says Gardenswartz.
For men, the hormone testosterone appears to fluctuate throughout the day, as well as throughout each month and potentially the seasons, which can affect mood, according to the American Psychological Association.
Lack of Sleep
The amount of sleep and quality of sleep you get can affect various aspects of your health, including your mood, according to the National Heart, Lung, and Blood Institute. Research suggests that sleep deprivation could be linked to stress and anger, for instance.
Not getting enough sleep can also lead to mood swings or more intensified symptoms of an existing mood disorder such as depression or bipolar disorder.
Mood Disorders and Related Mental Health Conditions
Mood swings can be a symptom of an underlying mood disorder such as depression or bipolar disorder, or another mental health condition such as borderline personality disorder, according to research.
For instance, someone with depression or seasonal affective disorder (a form of depression triggered by changing seasons) may have shifts in mood from feeling angry or irritable to feeling sad or hopeless.
People with borderline personality disorder often experience intense and highly changing moods, which can last from a few hours to a few days at a time, according to the National Institute of Mental Health.
People with bipolar disorder experience a more serious and longer-lasting form of mood swings known as mood episodes, according to the American Psychiatric Association (APA). There are three types: manic episodes (feeling elated or highly irritable), hypomanic episodes (a less severe form of manic episodes), and depressive episodes (feeling intense sadness, emptiness, or hopelessness).
Manic episodes last at least one week, and depressive episodes last at least two weeks, per the APA. The types of mood episodes an individual experiences and how often they experience them depends on the type of bipolar disorder they have.