Treatment or management of organic acidemias vary; eg see methylmalonic acidemia, propionic acidemia, isovaleric acidemia, and maple syrup urine disease.

As of 1984 there were no effective treatments for all of the conditions, though treatment for some included a limited protein/high carbohydrate diet, intravenous fluids, amino acid substitution, vitamin supplementation, carnitine, induced anabolism, and in some cases, tube-feeding.

As of 1993 ketothiolase deficiency and other OAs were managed by trying to restore biochemical and physiologic homeostasis; common therapies included restricting diet to avoid the precursor amino acids and use of compounds to either dispose of toxic metabolites or increase enzyme activity.

OAS must be managed in conjunction with the patient's other allergies, primarily the allergy to pollen. The symptom severity may wax and wane with the pollen levels. Published pollen counts and seasonal charts are useful but may be ineffective in cases of high wind or unusual weather, as pollen can travel hundreds of kilometers from other areas.

In addition, patients are advised to avoid the triggering foods, particularly nuts.

Peeling or cooking the foods has been shown to eliminate the effects of some allergens such as "mal d 1" (apple), but not others such as celery or strawberry. In the case of foods such as hazelnut, which have more than one allergen, cooking may eliminate one allergen but not the other.

Antihistamines may also relieve the symptoms of the allergy by blocking the immune pathway. Persons with a history of severe anaphylactic reaction may carry an injectable emergency dose of epinephrine (such as an EpiPen). Oral steroids may also be helpful. Allergy immunotherapy has been reported to improve or cure OAS in some patients. Immunotherapy with extracts containing birch pollen may benefit OAS sufferers of apple or hazelnut related to birch pollen-allergens. Even so, the increase in the amount of apple/hazelnut tolerated was small (from 12.6 to 32.6 g apple), and as a result, a patient's management of OAS would be limited.

Organic acidemia, also called organic aciduria, is a term used to classify a group of metabolic disorders which disrupt normal amino acid metabolism, particularly branched-chain amino acids, causing a buildup of acids which are usually not present.

The branched-chain amino acids include isoleucine, leucine and valine. Organic acids refer to the amino acids and certain odd-chained fatty acids which are affected by these disorders.

The four main types of organic acidemia are: methylmalonic acidemia, propionic acidemia, isovaleric acidemia, and maple syrup urine disease.

Allergies to a specific pollen are usually associated with OAS reactions to other certain foods. For instance, an allergy to ragweed is associated with OAS reactions to banana, watermelon, cantaloupe, honeydew, zucchini, and cucumber. This does not mean that all sufferers of an allergy to ragweed will experience adverse effects from all or even any of these foods. Reactions may be associated with one type of food, with new reactions to other foods developing later. However, reaction to one or more foods in any given category does not necessarily mean a person is allergic to all foods in that group.

It is unclear what causes alexithymia, though several theories have been proposed.

Early studies showed evidence that there may be an interhemispheric transfer deficit among people with alexithymia; that is, the emotional information from the right hemisphere of the brain is not being properly transferred to the language regions in the left hemisphere, as can be caused by a decreased corpus callosum, often present in psychiatric patients who have suffered severe childhood abuse. A neuropsychological study in 1997 indicated that alexithymia may be due to a disturbance to the right hemisphere of the brain, which is largely responsible for processing emotions. In addition, another neuropsychological model suggests that alexithymia may be related to a dysfunction of the anterior cingulate cortex. These studies have some shortcomings, however, and the empirical evidence about the neural mechanisms behind alexithymia remains inconclusive.

French psychoanalyst Joyce McDougall objected to the strong focus by clinicians on neurophysiological at the expense of psychological explanations for the genesis and operation of alexithymia, and introduced the alternative term "disaffectation" to stand for psychogenic alexithymia. For McDougall, the disaffected individual had at some point "experienced overwhelming emotion that threatened to attack their sense of integrity and identity", to which they applied psychological defenses to pulverize and eject all emotional representations from consciousness. A similar line of interpretation has been taken up using the methods of phenomenology. McDougall has also noted that all infants are born unable to identify, organize, and speak about their emotional experiences (the word "infans" is from the Latin "not speaking"), and are "by reason of their immaturity inevitably alexithymic". Based on this fact McDougall proposed in 1985 that the alexithymic part of an adult personality could be "an extremely arrested and infantile psychic structure". The first language of an infant is nonverbal facial expressions. The parent's emotional state is important for determining how any child might develop. Neglect or indifference to varying changes in a child's facial expressions without proper feedback can promote an invalidation of the facial expressions manifested by the child. The parent's ability to reflect self-awareness to the child is another important factor. If the adult is incapable of recognizing and distinguishing emotional expressions in the child, it can influence the child's capacity to understand emotional expressions.

Molecular genetic research into alexithymia remains minimal, but promising candidates have been identified from studies examining connections between certain genes and alexithymia among those with psychiatric conditions as well as the general population. A study recruiting a test population of Japanese males found higher scores on the Toronto Alexithymia Scale among those with the 5-HTTLPR homozygous long (L) allele. The 5-HTTLPR region on the serotonin transporter gene influences the transcription of the seretonin transporter that removes serotonin from the synaptic cleft, and is well studied for its association with numerous psychiatric disorders. Another study examining the 5-HT1A receptor, a receptor that binds serotonin, found higher levels of alexithymia among those with the G allele of the Rs6295 polymorphism within the HTR1A gene. Also, a study examining alexithymia in subjects with obsessive-compulsive disorder found higher alexithymia levels associated with the Val/Val allele of the Rs4680 polymorphism in the gene that encodes Catechol-O-methyltransferase (COMT), an enzyme which degrades catecholamine neurotransmitters such as dopamine. These links are tentative, and further research will be needed to clarify how these genes relate to the neurological anomalies found in the brains of people with alexithymia.

Although there is evidence for the role of environmental and neurological factors, the role and influence of genetic factors for developing alexithymia is still unclear. A single large scale Danish study suggested that genetic factors contributed noticeably to the development of alexithymia. However, such twin studies are controversial, as they suffer from the "equal environments assumption" and the "heritability" estimates in no way correspond to actual DNA structures.

Traumatic brain injury is also implicated in the development alexithymia, and those with traumatic brain injury are six times more likely to exhibit alexithymia.

Alexithymia is a personality construct characterized by the inability to identify and describe emotions in the self. The core characteristics of alexithymia are marked dysfunction in emotional awareness, social attachment, and interpersonal relating. Furthermore, people with alexithymia have difficulty in distinguishing and appreciating the emotions of others, which is thought to lead to unempathic and ineffective emotional responding. Alexithymia occurs in approximately 10% of the population and can occur with a number of psychiatric conditions.

The term "alexithymia" was coined by psychotherapist Peter Sifneos in 1973. The word comes from Greek α ("a", "no", the negating alpha privative), λέξις ("léxis", "word"), and θυμός ("thymos", "emotions", but understood by Sifneos as having the meaning "mood"), literally meaning "no words for mood".