Excessive sweating during pregnancy

By trimester

Weeks 1–13

1st trimester

Hormonal shifts start early, but excessive sweating is not usually the most prominent early symptom. If it does show up now alongside a fast heartbeat or unexplained weight loss, mention it, since thyroid conditions can also emerge or shift during this window.

Weeks 14–27

2nd trimester

As blood volume and metabolic rate keep climbing, whole-body sweating tends to become more noticeable. The same thermoregulatory shifts driving it are working as intended, helping you shed the extra internal heat that pregnancy generates.

Weeks 28–birth

3rd trimester

By the third trimester, both metabolic load and body mass are at their highest, so this is often when sweating feels most pronounced. It typically eases fairly soon after delivery as hormone levels and blood volume return toward pre-pregnancy levels.

What does the evidence show for excessive sweating?

• Pregnancy brings real thermoregulatory shifts, including a lower threshold for when sweating starts, more blood flow near the skin, and greater plasma volume, all of which increase the body's ability to shed the extra internal heat generated by the metabolic work of pregnancy. 1
• Pregnancy is listed among the recognized causes of generalized hyperhidrosis, sweating that affects the whole body rather than one area, alongside other endocrine changes like hyperthyroidism, diabetes, and menopause. This is distinct from focal hyperhidrosis, a separate condition affecting specific areas that usually starts at puberty. 2
• Focal hyperhidrosis affects specific areas, most often the underarms in about 79% of cases, though the hands, feet, and face can also be affected, and it involves a distinct dysfunction of the nervous system's sweat-gland signaling rather than a body-wide hormonal cause. 2
• An overactive thyroid during pregnancy can cause a fast or irregular heartbeat, shaky hands, and unexplained weight loss or a failure to gain the expected pregnancy weight. Some hyperthyroidism symptoms, such as trouble handling heat and tiredness, already overlap with ordinary pregnancy experiences, which is part of why the additional signs matter for telling the two apart. 3
• Normal body temperature is about 98.6°F (37°C), and hyperthermia is defined as the body absorbing more heat than it releases, from causes that include extreme exercise, hot tubs, saunas, and prolonged exposure to temperatures of 86°F (30°C) or higher, all situations that can trigger heavier sweating as the body works to cool itself. 4

Sweating all over vs. in specific spots

When should I call my provider about excessive sweating?

Excessive sweating alongside a rapid or irregular heartbeat, unexplained weight loss or a failure to gain expected pregnancy weight, or noticeably shaky hands is worth mentioning to your provider, since these can point to an overactive thyroid that needs evaluation. Sweating together with fever, chills, or generally feeling unwell also deserves prompt medical attention rather than being assumed to be a normal pregnancy symptom. Whatever the pattern, any symptom that feels beyond your usual range is a reason to call: obstetric teams expect these questions and would rather hear early than late.