Irritability and mood swings: causes, red flags and when to get help

Irritability is a lowered threshold for annoyance or anger. Mood lability means moods that swing quickly and out of proportion to events. Neither is a diagnosis; both are features of many different conditions, which is why the useful questions are when it started, whether it follows a pattern, and what comes with it, such as poor sleep, palpitations, tremor, exhaustion or a low mood.

Families and colleagues often notice before the person does. Asking someone close what they have observed can be part of the assessment, and keeping a short diary of mood, sleep, periods and caffeine or alcohol for two or three weeks gives a GP something concrete to work from.

The table groups the causes named in NHS and NICE sources. More than one can apply at the same time.

Irritability alone is not an emergency. The features that raise urgency are those suggesting a crisis or a serious physical cause. The NHS generalised anxiety disorder page tells readers to seek urgent help if they or someone they know is having a mental health crisis or emergency, whatever they are going through. Thoughts of harming yourself or others, or feeling unable to keep safe, need immediate help from a GP, NHS 111, a crisis line or 999.

Sudden confusion, a severe headache, a fit, collapse or a drunk-like state in someone who has not been drinking needs emergency assessment; the NHS says sudden confusion warrants A&E or 999. For people with diabetes, irritability with sweating, shaking, tingling lips or confusion may be a hypo, and the NHS describes eating or drinking fast-acting sugar, with 999 if the person is unresponsive.

Irritability with weight loss, a persistent racing heartbeat, tremor and heat intolerance suggests an overactive thyroid and deserves a GP visit soon.

• Thoughts of self-harm, suicide or harming others.

• Violent outbursts or aggression that put anyone at risk.

• Sudden confusion, severe headache, collapse or a seizure.

• Palpitations, tremor, weight loss and sweating with irritability.

• Irritability that has persisted for weeks and is harming relationships, work or sleep.

• A marked change in personality in an older person, which needs assessment rather than reassurance.

The GP typically asks when it began, whether it is constant or cyclical, how sleep, appetite, energy and mood are, about alcohol, caffeine and drugs, medicines, life stresses, menstrual and menopausal history, and whether there are physical symptoms such as palpitations, tremor, weight change or heat intolerance. CKS says PMS is confirmed by a daily symptom diary over two or three cycles showing symptoms in the second half of the cycle that settle with the period, followed by a symptom-free week, and by the absence of other conditions such as depression, hypothyroidism, anaemia, irritable bowel syndrome and endometriosis.

For anxiety, the NHS says a GP will ask about your worries and physical symptoms and asks you to be honest. The examination may include pulse, blood pressure, weight and the thyroid gland.

Blood tests commonly include thyroid function (the NHS says a GP can arrange a blood test to check how well the thyroid works), a full blood count for anaemia and, where relevant, blood sugar. FSH is not used to diagnose menopause in healthy people aged 45 or over with typical symptoms, according to CKS.

Many people need no tests because the pattern, such as a clear premenstrual rhythm or a period of poor sleep, explains the problem.

Treatment follows the cause. For PMS the NHS suggests regular exercise, a healthy balanced diet with frequent smaller meals, enough sleep, stress reduction through yoga or meditation, painkillers such as ibuprofen or paracetamol for pain, avoiding smoking and excess alcohol and keeping a symptom diary. A GP may offer hormonal treatment such as the combined contraceptive pill, cognitive behavioural therapy or antidepressants. CKS lists a drospirenone-containing pill, CBT and an SSRI for severe symptoms, with a review after 2 months.

For insomnia, the NHS recommends consistent sleep habits, avoiding caffeine, alcohol and nicotine in the hours before bed and cognitive behavioural therapy. For menopause, lifestyle measures, CBT and HRT are options. Anxiety is treated with talking therapies, which adults can refer themselves to in England, and medicines where appropriate. An overactive thyroid is usually treatable with medicine, radioiodine or surgery.

A GP is the first stop. The NHS says adults can refer themselves to NHS talking therapies for anxiety and depression without a GP referral. A pharmacist can advise on sleep aids and painkillers. Specialist referral, to a gynaecologist, psychiatrist or counsellor for PMS, an endocrinologist for thyroid disease or a mental health team, is considered when first-line treatment does not help.