Hypodermis

Hypodermis — the deepest layer of skin, also called the subcutaneous layer or subcutis, made up largely of fat and connective tissue beneath the dermis. It cushions the body, insulates against heat loss, stores energy, and anchors the skin to underlying muscle and bone.

Key points

• The hypodermis is composed mainly of adipose (fat) cells organized into lobules separated by fibrous connective tissue.
• It provides insulation and shock absorption, protecting deeper structures from temperature changes and physical impact.
• Larger blood vessels and nerves pass through the hypodermis before branching into the dermis above it.
• Its thickness varies by body area, age, sex, and individual factors, influencing skin contour and firmness.

Frequently asked

Is the hypodermis considered part of the skin?

It is often described as the deepest layer of the skin, though some anatomists classify it as a separate subcutaneous layer that connects the skin to underlying tissues.

What does the hypodermis do for the skin's appearance?

The fat and connective tissue of the hypodermis support the skin from below, and changes in this layer over time can affect the skin's fullness and contour.

Related topics

• What Is a Humectant?
• What Is the Skin Barrier?
• The Hypodermis (Subcutaneous Layer)

This is a foundational entry in the SYNC Skin Encyclopedia and is expanded over time. Educational information only — not medical advice.