Ever wonder why you feel like crying over a pet food commercial one day but can watch a tearjerker movie completely unfazed the next? Or why your weight seems to fluctuate despite eating the same ...

Metabolism and thyroid hormones: a close relationship. Because they have such a big impact on how your body uses energy, thyroid hormones are often called the metabolic regulators. Your body burns ...

Male hormone levels maintain day-to-day stability while female hormones experience continuous changes throughout both the menstrual cycle and various life stages.

Reviewed by Felix Gussone, MD. Your endocrine system is a network of glands that produce and release hormones directly into your bloodstream. These hormones act like tiny, powerful messengers, ...

Sunlight activates hormones essential for mood, sleep and reproductive health — that’s why it’s important to go outside when ...

Endocrine glands secrete hormones into the bloodstream, while exocrine glands secrete substances, such as sweat or enzymes, into organs or onto the surface of the body. The two main types of glands in ...

Free-living great tits differ considerably in the level of stress hormones in their blood. A research project at the Max Planck Institute for Biological Intelligence (in foundation) studied the birds ...