Body odor often abbreviated as
B.O., or
bromhidrosis (also called
osmidrosis and
ozochrotia) (also known as "Apocrine bromhidrosis," "Bromidrosis," "Fetid sweat," "Body smell," "Malodorous sweating," and "Osmidrosis") is the
smellAn odor or odour is caused by one or more volatilized chemical compounds, generally at a very low concentration, that humans or other animals perceive by the sense of olfaction. Odors are also called smells, which can refer to both pleasant and unpleasant odors...
of bacteria growing on the
bodyWith regard to living things, a body is the physical body of an individual. "Body" often is used in connection with appearance, health issues and death...
. These bacteria multiply rapidly in the presence of
sweatSWEAT is an OLN/TSN show hosted by Julie Zwillich that aired in 2003-2004.Each of the 13 half-hour episodes of SWEAT features a different outdoor sport: kayaking, mountain biking, ice hockey, beach volleyball, soccer, windsurfing, rowing, Ultimate, triathlon, wakeboarding, snowboarding, telemark...
, but sweat itself is almost completely odorless to humans.
Body odor often abbreviated as
B.O., or
bromhidrosis (also called
osmidrosis and
ozochrotia) (also known as "Apocrine bromhidrosis," "Bromidrosis," "Fetid sweat," "Body smell," "Malodorous sweating," and "Osmidrosis") is the
smellAn odor or odour is caused by one or more volatilized chemical compounds, generally at a very low concentration, that humans or other animals perceive by the sense of olfaction. Odors are also called smells, which can refer to both pleasant and unpleasant odors...
of bacteria growing on the
bodyWith regard to living things, a body is the physical body of an individual. "Body" often is used in connection with appearance, health issues and death...
. These bacteria multiply rapidly in the presence of
sweatSWEAT is an OLN/TSN show hosted by Julie Zwillich that aired in 2003-2004.Each of the 13 half-hour episodes of SWEAT features a different outdoor sport: kayaking, mountain biking, ice hockey, beach volleyball, soccer, windsurfing, rowing, Ultimate, triathlon, wakeboarding, snowboarding, telemark...
, but sweat itself is almost completely odorless to humans. Body odor is associated with the
hairHair is a protein filament that grows through the epidermis from follicles deep within the dermis. The fine, soft hair found on many nonhuman mammals is typically called fur; wool is the characteristically curly hair found on sheep and goats. Found exclusively in mammals, hair is one of the...
,
feetThe sole is the bottom of the foot.In humans is the sole of the foot anatomically referred to as the plantar aspect. The equivalent surface in ungulates is the hoof.- Human sole :...
, hands,
groinIn human anatomy, the groin areas are the two creases at the junction of the torso with the legs, on either side of the pubic area. A pulled groin muscle usually refers to a painful injury sustained by straining the hip adduction muscle....
(upper medial thigh),
anusThe human Anus
,
skinThe skin is the outer covering of the body. In humans, it is the largest organ of the integumentary system made up of multiple layers of mesodermal tissue, and guards the underlying muscles, bones, ligaments and internal organs. Skin of a different nature exists in amphibians, reptiles, birds...
in general, armpits, genitals,
pubic hairPubic hair is hair in the frontal genital area, the crotch, and sometimes at the top of the inside of the legs; these areas form the pubic region....
,
belly buttonThe navel is a scar on the abdomen, caused when the umbilical cord is removed from a newborn baby. All placental mammals have a navel...
and
earThe ear is the organ that detects sound. The vertebrate ear shows a common biology from fish to humans, with variations in structure according to order and species. It not only acts as a receiver for sound, but plays a major role in the sense of balance and body position...
s (behind the ears).
Specificity
Body odour can smell pleasant and specific to the individual, and can be used to identify people, though this is more often done by
dogThe dog is a domesticated form of the Gray Wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties. The domestic dog has been one of the most widely kept working and companion animals in human history...
s and other animals than by
humanHumans are bipedal primates belonging to the species Homo sapiens in Hominidae, the great ape family. They are the only surviving member of the genus Homo. Humans have a highly developed brain, capable of abstract reasoning, language, introspection, and problem solving...
s. An individual's body odor is also influenced by
dietIn nutrition, the diet is the sum of food consumed by a person or other organism. Dietary habits are the habitual decisions an individual or culture makes when choosing what foods to eat. Although humans are omnivores, each culture holds some food preferences and some food taboos. Individual...
,
genderGender commonly refers to the set of characteristics that humans perceive as distinguishing between male and female entities, extending from one's biological sex to, in humans, one's social role or gender identity. As a term, "gender" has more than one valid definition...
,
geneticsGenetics, , a discipline of biology, is the science of heredity and variation in living organisms. The fact that living things inherit traits from their parents has been used since prehistoric times to improve crop plants and animals through selective breeding...
,
healthAt the of the creation of the World Health Organization , in 1948, Health was defined as being "a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity"....
and
medicationA pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...
.
Propionic acidPropionic acid is a naturally-occurring carboxylic acid with chemical formula CH3CH2COOH. It is a clear liquid with a pungent odor...
(propanoic acid) is present in many sweat samples. This acid is a breakdown product of some
amino acidAmino acids are molecules containing an amine group, a carboxylic acid group and one of the twenty R-groups. These molecules are particularly important in biochemistry, where this term refers to alpha-amino acids with the general formula H
2NCHRCOOH, where R is an organic substituent...
s by propionibacteria, which thrive in the ducts of adolescent and adult sebaceous glands. Because propionic acid is chemically similar to
acetic acidAcetic acid, CH
3COOH, also known as ethanoic acid, is an organic acid which gives vinegar its sour taste and pungent smell. It is a weak acid, in that it is only partially dissociated acid in aqueous solution...
with similar physical characteristics including odor, body odors may be identified as having a vinegar-like smell by certain persons. Isovaleric acid (3-methyl butanoic acid) is the other source of body odor as a result of actions of the bacteria
Staphylococcus epidermidisStaphylococcus epidermidis is one of thirty three known species belonging to the genus Staphylococcus. It is part of our human flora, and consequently part of skin flora. It can also be found the in mucous membranes and in animals. Due to contamination, it is probably the most common species found...
, which is also present in several strong cheese types.
Genetics
Body odor is largely influenced by
major histocompatibility complexThe major histocompatibility complex is a large genomic region or gene family found in most vertebrates. It is the most gene-dense region of the mammalian genome and plays an important role in the immune system and autoimmunity. The diversity of MHC is important in the immune diversity in the...
(MHC) molecules. These are genetically determined and play an important role in
immunityImmunity is a biological term that describes a state of having sufficient biological defenses to avoid infection, disease, or other unwanted biological invasion. Immunity involves both specific and non-specific components. The non-specific components act either as barriers or as eliminators of wide...
of the organism. The
vomeronasal organThe vomeronasal organ , or Jacobson's organ, is an auxiliary olfactory sense organ that is found in many animals. It was discovered by Ludwig Jacobson in 1813....
contains cells sensitive to MHC molecules in a genotype-specific way. Experiments on animals and volunteers have shown that potential sexual partners tend to be perceived more attractive if their MHC composition is substantially different. This behavior pattern promotes variability of the immune system of individuals in the population, thus making the population more robust against new diseases.
A recent study suggests that body odor is genetically determined by a gene that also codes the type of
earwaxEarwax, also known by the medical term cerumen, is a yellowish waxy substance secreted in the ear canal of humans and many other mammals. It protects the skin of the human ear canal, assists in cleaning and lubrication, and also provides some protection from bacteria, fungi, insects and water...
one has. East Asians (those of Chinese, Japanese and Korean descent) have the type of sweat glands which even after hitting puberty still don't produce the chemicals found in the perspiration of other ancestral groups.
East Asians evidently have a greater chance of having the 'dry' earwax type and reduced axial sweating and odor. This may be due to adaptation to colder climates.
Alterations
Body odor perceived as offensive may be reduced or prevented by using
deodorantDeodorants are substances applied to the body mainly to reduce body odor which is caused by the bacterial breakdown of perspiration. A subgroup of deodorants are "antiperspirants", which prevent odor and reduce sweat produced by parts of the body...
s, and although body odor is commonly associated with
hygieneHygiene, refers to the set of practices associated with the preservation of health and healthy living. Hygiene is a concept related to medicine, as well as to personal and professional care practices related to most aspects of living, although it is most often associated with cleanliness and...
, its presentation can be affected by changes in
dietIn nutrition, the diet is the sum of food consumed by a person or other organism. Dietary habits are the habitual decisions an individual or culture makes when choosing what foods to eat. Although humans are omnivores, each culture holds some food preferences and some food taboos. Individual...
as well as those other factors discussed above.
See also
- Butyric acid
Butyric acid , also known under the systematic name butanoic acid, is a carboxylic acid with the structural formula CH3CH2CH2-COOH. Salts and esters of butyric acid are known as butyrates or butanoates...
- Foot odor
Foot odor is a type of body odor that affects the feet of humans and is generally considered to be an unpleasant smell.-Cause:The main causes is acid sweat not because of the sweat itself which has no odor, but because it creates a perfect environment for certain bacteria to grow and to produce...
- Halitosis (bad breath)
Halitosis, or most commonly bad breath are terms used to describe noticeably unpleasant odors exhaled in breathing – whether the smell is from an oral source due to bacteria....
- Olfactophilia
Olfactophilia or osmolagnia is a paraphilia for, and sexual attraction to, or sexual arousal by smells and odors emanating from the body, especially the sexual areas...
- Pheromone
A pheromone is a chemical signal that triggers a natural response in another member of the same species. There are alarm pheromones, food trail pheromones, sex pheromones, and many others that affect behavior or physiology. Their use among insects has been particularly well documented...
- Sweat gland
Sweat glands are exocrine glands, found in the skin of all mammal species, that are used for body temperature regulation. In humans a system of apocrine - and merocrine sweat glands is the main method of cooling. Many other mammals rely on panting or other means as a primary source of cooling, but...
- Trimethylaminuria
Trimethylaminuria , also known as fish odor syndrome or fish malodor syndrome,, is a rare metabolic disorder that causes a defect in the normal production of the enzyme Flavin containing monooxygenase 3...
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