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What Are the Common Causes of Sudden Mood Swings?

Sheri Cyprus
Sheri Cyprus

The common causes of sudden mood swings range from brain or other disorders to substance abuse and side effects of some medications. Mood changes may occur suddenly in a new environment or situation. Pregnancy and menstrual cycles also commonly cause mood swings as do hormones during adolescence. Other common causes of mood swings that may appear suddenly are cardiovascular and lung disease as well as seizures and strokes.

When a person suffers a stroke, brain damage may cause extreme emotions as well as changes in thoughts and behaviors. Sudden depression and anger may also be caused from the stroke sufferer's feelings about losing speech, movement or other physical skills. Seizures and sudden mood changes are related in that depression or irritability may occur just minutes before a seizure. Sudden mood swings in cardiovascular or lung disease may occur due to the brain receiving less oxygen and blood nutrients. The individual may suddenly feel disoriented or agitated and experience difficulty in concentrating.

A doctor can prescribe medication and deliver psychological therapy for mood swings if necessary.
A doctor can prescribe medication and deliver psychological therapy for mood swings if necessary.

During adolescence, the increase of sex hormones in the body may cause sudden mood changes. The experience of abrupt changes in mood or emotions typically don't last, though in females they may recur before each menstrual cycle. Premenstrual disorder (PMS) is a common cause of mood swings that may present as mild sadness or irritability about one or two weeks before the start of each menstruation cycle. Premenstrual dysphoric disorder is a more severe form of PMS with stronger mood swings typically occurring. Mood swings during or after pregnancy that appear suddenly are also common and usually due to hormonal changes.

Pregnant women may experience hormonal mood swings.
Pregnant women may experience hormonal mood swings.

In a stressful situation or new environment, it's common to experience sudden mood swings such as an easy going attitude than changes into anxiety or irritability. The chemical signals to the brain may change due to stress or fear in unfamiliar surroundings or new or difficult situations. Hormones such as adrenaline may create a sudden change in mood such as a "sped up" feeling and a rush of energy or urgency.

Stressful situations may cause sudden mood swings, including irritability.
Stressful situations may cause sudden mood swings, including irritability.

Some medications may cause sudden changes in mood due to changes the chemicals create when mixing with brain chemistry. Substance abuse, either of drugs or alcohol, is also a common cause of sudden mood swings relating to brain chemistry changes. Brain and mood disorders also cause mood changes of which a chemical imbalance may be at the root. Sudden shifts in mood are extremely common in bipolar disorder, which used to be called manic depression because of the cycles of elation contrasting with depressive episodes. People with rapid cycling or mixed episode types of bipolar disorders may especially be prone to sudden changes in mood.

Discussion Comments

bear78

@turquoise-- It's not a good idea to jump to conclusions, because there are many other causes of mood swings too. It can be a health condition or a psychological condition. How old is your friend? He could just be going through a hormonal change.

I have severe mood swings a week before my menstruation. I become a monster and pick fights with everyone around me. I return to normal after a week. Hormones play a very big part in our mood and emotions, more so than we realize.

turquoise

@ysmina-- Drug abuse can definitely cause mood swings. I was abusing prescription drugs for a while and I know from my experiences that drug addiction causes a chemical imbalance in the brain. It can cause personality changes and sudden mood changes. Like I would be very happy one moment and absolutely miserable the next. It was not normal at all.

I got treatment and have been clean for fifteen years. If possible, try to support your friend and encourage him to stop without pressurizing him.

ysmina

I think my friend might be abusing drugs. He has been acting very weird lately. He used to be a very calm guy and now he has sudden mood swings and becomes angry and aggressive. I can't recognize him, it's like he's a different person.

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    • A doctor can prescribe medication and deliver psychological therapy for mood swings if necessary.
      By: Alexander Raths
      A doctor can prescribe medication and deliver psychological therapy for mood swings if necessary.
    • Pregnant women may experience hormonal mood swings.
      By: igorborodin
      Pregnant women may experience hormonal mood swings.
    • Stressful situations may cause sudden mood swings, including irritability.
      By: nebari
      Stressful situations may cause sudden mood swings, including irritability.
    • Lung disease is considered a common cause of sudden mood swings.
      By: CLIPAREA.com
      Lung disease is considered a common cause of sudden mood swings.
    • PMS is often a cause of major mood swings in women.
      By: lukasmajercik
      PMS is often a cause of major mood swings in women.
    • Getting regular exercise can help lessen mood swings and irritability.
      By: Minerva Studio
      Getting regular exercise can help lessen mood swings and irritability.
    • A person's diet often is a factor in their mood.
      By: Ana Blazic Pavlovic
      A person's diet often is a factor in their mood.