Sudden weight gain can be alarming, especially if you haven't made any major changes to your diet or exercise routine.
There are a number of possible causes, including:
Medical conditions: Certain medical conditions, such as hypothyroidism, Cushing's syndrome, and polycystic ovary syndrome (PCOS), can cause sudden weight gain
Medications: Some medications, such as corticosteroids, antidepressants, and antipsychotics, can also lead to weight gain
Fluid retention: Fluid retention can cause a temporary increase in weight.
Changes in hormones: Hormonal changes, such as those that occur during menopause and perimenopause, can also contribute to weight gain
Stress: Stress can lead to the production of the hormone cortisol, which can promote weight gain, especially around the midsection
Lack of sleep: When you don't get enough sleep, your body produces more of the stress hormone cortisol, which can lead to weight gain
Quitting smoking: Many people gain weight after quitting smoking.