Ana or ANA may refer to:
Anal sex or anal intercourse is generally the insertion and thrusting of the erect penis into a person's anus, or anus and rectum, for sexual pleasure.
Anabolic steroids, also known more properly as anabolic-androgenic steroids (AAS), are steroidal androgens that include natural androgens like testosterone as well as synthetic substances that are structurally related and have similar effects to testosterone.
Anarchism is a political philosophy that advocates self-governed societies based on voluntary institutions.
Anatomy is the branch of biology concerned with the study of the structure of organisms and their parts.
Anarcho-capitalism is a political philosophy that advocates the elimination of the state in favor of individual sovereignty, private property, and free markets.
An analgesic or painkiller is any member of the group of drugs used to achieve analgesia, relief from pain.
In electronics, an analog-to-digital converter (ADC, A/D, A–D, or A-to-D) is a system that converts an analog signal, such as a sound picked up by a microphone or light entering a digital camera, into a digital signal.
Standard anatomical terms of location deal unambiguously with the anatomy of animals, including humans.
Anaphylaxis is a serious allergic reaction that is rapid in onset and may cause death. It typically causes more than one of the following: an itchy rash, throat or tongue swelling, shortness of breath, vomiting, lightheadedness, and low blood pressure.