Glands are spread across nearly every region of your body, from the brain down to the skin. Some are tucked deep inside the skull, others sit in the neck, chest, abdomen, and pelvis, and millions more are embedded in the skin itself. Understanding where they are helps make sense of how hormones, digestion, immunity, and other essential functions actually work.
Glands in the Brain
Three key glands sit within or just below the brain. The hypothalamus occupies roughly 2 percent of total brain volume and lies at the base of the brain, just below a structure called the thalamus. It acts as a command center, sending chemical signals that tell other glands what to do.
Directly beneath the hypothalamus, the pituitary gland rests in a small bony pocket of the skull called the sella turcica, right behind the bridge of your nose. Despite being only about the size of a pea, it releases hormones that control growth, metabolism, and reproduction. The optic nerves cross just above it, which is why a pituitary tumor can sometimes cause vision changes.
The pineal gland sits deeper in the brain, toward the back and center. It produces melatonin, the hormone that regulates your sleep-wake cycle. Its location near the brain’s third ventricle was noted as far back as the ancient physician Galen.
Glands in the Neck
The thyroid gland wraps around the front of your windpipe at roughly the base of the neck, overlying the area from the fifth cervical vertebra down to the first thoracic vertebra. It has two lobes connected by a narrow bridge (the isthmus) that crosses the second and third rings of the trachea. You can sometimes feel it by placing your fingers just below your Adam’s apple and swallowing.
The parathyroid glands are four tiny structures, each about the size of a grain of rice, sitting on the back surface of the thyroid. They regulate calcium levels in the blood. Because of their small size and close attachment to the thyroid, surgeons must be careful to preserve them during any thyroid operation.
Glands in the Chest
The thymus sits in the upper chest, behind the breastbone and in front of the heart’s outer covering and major blood vessels. It plays a critical role in training immune cells during childhood, and it’s proportionally large in infants, filling a significant portion of the upper chest cavity. By early adulthood the thymus begins shrinking and is gradually replaced by fatty tissue. On imaging, the normal thymus measures up to 18 mm wide before age 20 and shrinks to about 13 mm in adults. By age 40, it’s often indistinguishable from surrounding fat on a scan.
Glands in the Abdomen
The adrenal glands are small, triangular structures that sit on top of each kidney, deep in the back of the abdomen. They produce stress hormones like cortisol and adrenaline, along with small amounts of sex hormones.
The pancreas lies horizontally behind the stomach, stretching from the curve of the small intestine on the right toward the spleen on the left. It functions as both an exocrine gland (releasing digestive enzymes into the intestine) and an endocrine gland (secreting insulin and glucagon into the bloodstream to manage blood sugar).
The liver, located mostly in the right upper portion of the abdomen just beneath the diaphragm, is the body’s largest internal organ and also qualifies as a gland. Its exocrine role involves producing bile, which is stored in the gallbladder and released into the intestine to help digest fats. Its endocrine role includes helping regulate blood sugar alongside the pancreas.
Glands in the Head and Mouth
Three pairs of major salivary glands produce most of the saliva in your mouth. The parotid glands are the largest, sitting just in front of each ear. The submandibular glands are tucked beneath the jawbone on either side. The sublingual glands lie under the floor of your mouth, below each side of the tongue. Together they produce roughly a liter of saliva per day, which aids digestion and protects your teeth.
The lacrimal glands are located within the eye socket, above the outer corner of each eye. They produce the watery layer of your tears, keeping the eye surface moist and flushing out debris.
Glands in the Pelvis
The ovaries are the primary reproductive glands in females. They sit in shallow depressions called ovarian fossae, one on each side of the uterus, along the lateral walls of the pelvic cavity. Each ovary is roughly the size of an almond and releases both eggs and hormones like estrogen and progesterone.
The testes are the primary reproductive glands in males. Unlike most other glands, they’re located outside the main body cavity, housed within the scrotum. This external position keeps them slightly cooler than core body temperature, which is necessary for healthy sperm production. The testes also produce testosterone.
Glands in the Skin
Your skin contains millions of tiny glands. Sebaceous glands are found in the middle layer of skin (the dermis), typically nestled in the angle between a hair follicle and the small muscle that makes hair stand on end. They secrete an oily substance that keeps skin and hair moisturized. They’re present nearly everywhere on the body except the palms of your hands and the soles of your feet.
Sweat glands come in two main types. Eccrine sweat glands are distributed across almost the entire body surface, with the highest concentrations on your palms, soles, and forehead. They release a watery sweat directly onto the skin to help regulate temperature. Apocrine sweat glands are concentrated in the armpits and groin area. They release a thicker fluid into hair follicles, and when bacteria on the skin break that fluid down, it produces body odor.
Lymph Nodes: Not Glands, but Often Called That
When people say their “glands are swollen,” they’re almost always referring to lymph nodes. Lymph nodes are small, bean-shaped structures that filter fluid and help fight infection, but they don’t secrete hormones or other substances the way true glands do. An adult has roughly 800 lymph nodes scattered throughout the body. The clusters you’re most likely to feel when they swell are in the neck, under the jaw, in the armpits, and in the groin. Deeper clusters also exist in the chest and abdomen, surrounding major blood vessels. Swollen lymph nodes usually signal that your immune system is actively responding to an infection nearby.