Sudden fatigue during pregnancy: what to know

Pregnancy can increase the body's energy demands and alter sleep, appetite, circulation and hormone levels. Nausea, emotional strain, poor sleep or not eating regularly can make tiredness feel abrupt. Fatigue may also accompany anaemia, when there are not enough healthy red blood cells to carry oxygen efficiently. Your clinician may consider thyroid problems, infection, dehydration or another medical issue if the change is pronounced. Anaemia, coeliac disease, chronic kidney disease and COVID-19 are examples of conditions that can include fatigue, but fatigue alone cannot identify its cause.

Notice when the change began, whether rest helps, and whether you also have breathlessness, dizziness, palpitations, fever, vomiting, pain, swelling or reduced ability to manage daily tasks.

Rest when possible, keep a regular sleep routine and eat small balanced meals if nausea makes larger meals difficult. Drink fluids regularly, especially after vomiting or in hot weather. Gentle movement may help if you feel well enough, but stop if it causes dizziness or breathlessness. Do not start iron, herbal products or other supplements to treat fatigue without checking that they are suitable in pregnancy. Arrange a pregnancy-care appointment if the tiredness is new, persistent, worsening or interfering with work, eating, washing or walking.

Seek urgent medical care for severe breathlessness, chest pain, fainting, confusion, a severe headache, heavy bleeding, severe abdominal pain, inability to keep fluids down or a sudden major reduction in your ability to function. Contact your maternity team promptly for fever, painful urination, marked dizziness, a racing heartbeat or fatigue with swelling and visual changes. The urgency can depend on your stage of pregnancy and accompanying symptoms.

Ask whether your symptoms warrant a blood count or other tests, whether your medicines and supplements are appropriate, and which warning signs should prompt same-day care. Tell them about sleep, food and fluid intake, bleeding, mood changes, infections, and any change in fetal movement when that applies to your stage of pregnancy.