PMS vs bipolar disorder: how to tell them apart

PMS is a pattern tied to your menstrual cycle. Symptoms show up in the one to two weeks before your period and ease once bleeding starts, including:

• irritability
• low mood
• bloating
• headaches

Bipolar disorder is a separate mental health diagnosis. It involves distinct episodes of mania, hypomania or depression that can last for weeks and appear at any point in your cycle, not only the days before your period.

The two conditions can feel identical in a single hard moment. An irritable day feels the same whether its cause is hormonal or not. What separates them is timing: PMS switches on and off with your cycle, while bipolar disorder runs on its own schedule, even though hormone shifts can make bipolar symptoms worse at certain points [1].

If your premenstrual symptoms are severe enough to affect your daily life on their own, read more about PMDD (premenstrual dysphoric disorder), the more severe form of PMS.

Yes, the two can occur together, and more often than chance alone would predict. Women with bipolar disorder, especially bipolar II, have higher rates of PMS or PMDD than women without bipolar disorder, and women with PMDD have a higher rate of bipolar diagnoses too [2].

One systematic review found a wide range of overlap between the two conditions:

• 10 to 15% of people diagnosed with PMDD also met criteria for bipolar disorder
• 27 to 76% of people with bipolar disorder met criteria for PMDD [4]

Mood disorders overall have been linked to comorbid premenstrual disorders in 20 to 70% of cases in prior research cited by one meta-analysis, which itself found consistently high pooled comorbidity rates between PMDD/PMS and mood disorders [5]. That wide range exists partly because so few studies track symptoms daily, the only way to confirm either diagnosis with confidence [4].

There's a third pattern worth knowing about: when an existing condition like bipolar disorder gets worse before your period but stays present the rest of the month, that has its own name, premenstrual exacerbation. For the PMDD-specific version of this comparison, see PMDD vs bipolar disorder: how to tell them apart.

PMS, PMDD and bipolar disorder share enough symptoms that it's easy to mix them up, especially in a single appointment with a doctor who hasn't seen the pattern over time.

Both can bring:

• irritability or anger that feels out of proportion
• mood swings, from flat to keyed up
• trouble sleeping or sleeping too much
• trouble concentrating
• appetite changes

Bipolar disorder can also bring symptoms PMS and PMDD don't typically include, like unusually high energy, less need for sleep, or racing thoughts during a manic or hypomanic episode.

The symptoms alone don't tell you which condition you're dealing with. What matters is when they show up, how long they last, and what the rest of the month looks like.

Doctors rely on your history, not a blood test. Women with severe PMS usually have normal estrogen and follicle-stimulating hormone levels, so hormone testing can't separate PMS from bipolar disorder [1]. What matters is the pattern over time, which is why the diagnosis depends on what you and your doctor can see across months, not one appointment.

A history of postnatal depression or a life with many genuinely good days a month, alongside physical symptoms like breast tenderness, bloating or headaches, points toward PMS rather than bipolar disorder [1].

Charting is the one tool that reliably tells PMS and PMDD apart from bipolar disorder, because it shows the timing that a single conversation can't [7]. You rate your mood and physical symptoms daily for at least two menstrual cycles, then look at where the low points fall.

A chart where mood drops with every luteal phase and lifts within days of bleeding supports PMS or PMDD. A chart where mood episodes last for weeks without tracking the cycle points toward bipolar disorder, or toward both conditions together [2].

The DRSP chart is the standard tool for this, and how to get a PMDD diagnosis walks through what to bring to that first appointment.

Niyora is a PMS and PMDD support app. Its estimated PMS window can help you notice your own timing early, before you sit down to fill out a full two-cycle chart for a clinician.

Treatment follows the diagnosis, which is one more reason getting it right matters.

For PMS and PMDD, options a doctor might discuss include:

• SSRIs, taken daily or only in the two weeks before your period, which improved mood and physical symptoms in trials [6]
• certain hormonal contraceptives
• cognitive behavioral therapy (CBT)
• vitamin D, if testing shows you're low in it [3]
• Vitex agnus castus, which showed positive results across eight small trials, though the trials varied enough in design that the evidence stays limited [8]

For bipolar disorder, treatment usually means a mood stabilizer or antipsychotic, prescribed and monitored by a psychiatrist. One case report describes young women with severe PMS who didn't respond to the antidepressants and mood-stabilizing drugs typically used for bipolar disorder, which is part of why the right diagnosis comes first [1].

A doctor decides which path fits your pattern, and that decision rests on the chart you bring in, not a guess made in one visit. If you're not sure where your symptoms fall, the quiz on how much PMS is affecting you is a starting point before you chart.