Examples include:

disorders causing delirium (toxic psychosis), in which consciousness is disturbed
neurodevelopmental disorders and chromosomal abnormalities, including velocardiofacial syndrome
neurodegenerative disorders, such as Alzheimers disease, dementia with Lewy bodies, and Parkinsons disease
focal neurological disease, such as stroke, brain tumors, multiple sclerosis, and some forms of epilepsy
malignancy (typically via masses in the brain, paraneoplastic syndromes)
infectious and postinfectious syndromes, including infections causing delirium, viral encephalitis, HIV/AIDS, malaria, syphilis
endocrine disease, such as hypothyroidism, hyperthyroidism, Cushings syndrome, hypoparathyroidism and hyperparathyroidism; sex hormones also affect psychotic symptoms and sometimes giving birth can provoke psychosis, termed postpartum psychosis
inborn errors of metabolism, such as Wilsons disease, porphyria, and homocysteinemia. nutritional deficiency, such as vitamin B12 deficiency
other acquired metabolic disorders, including electrolyte disturbances such as hypocalcemia, hypernatremia, hyponatremia, hypokalemia, hypomagnesemia, hypermagnesemia, hypercalcemia, and hypophosphatemia, but also hypoglycemia, hypoxia, and failure of the liver or kidneys
autoimmune and related disorders, such as systemic lupus erythematosus (lupus, SLE), sarcoidosis, Hashimotos encephalopathy, anti-NMDA-receptor encephalitis, and non-celiac gluten sensitivity
poisoning, by therapeutic drugs (see below), recreational drugs (see below), and a range of plants, fungi, metals, organic compounds, and a few animal toxins
sleep disorders, such as in narcolepsy (in which REM sleep intrudes into wakefulness)
parasitic diseases, such as neurocysticercosis
huntington disease

Psychoactive drugs
Various psychoactive substances (both legal and illegal) have been implicated in causing, exacerbating, or precipitating psychotic states or disorders in users, with varying levels of evidence. This may be upon intoxication for a more prolonged period after use, or upon withdrawal.
In countries such as the United States where there exists a predominantly biomedical understanding of the body, the mind and in turn, mental health, subjects were found to report their hallucinations as having ‘violent content’ and self-describing as ‘crazy’. This lived experience is at odds with the lived experience of subjects in Accra, Ghana, who describe the voices they hear as having ‘spiritual meaning’ and are often reported as positive in nature; or subjects in Chennai, India, who describe their hallucinations as kin, family members or close friends, and offering guidance.These differences are attributed to ‘social kindling’ or how ones social context shapes how an individual interprets and experiences sensations such as hallucinations. This concept aligns with pre-existing cognitive theory such as reality modelling and is supported by recent research that demonstrates that individuals with psychosis can be taught to attend to their hallucinations differently, which in turn alters the hallucinations themselves. Such research creates pathways for social or community-based treatment, such as reality monitoring, for individuals with schizophrenia and other psychotic disorders, providing alternatives to, or supplementing traditional pharmacologic management. Cross-cultural studies explore the way in which psychosis varies in different cultures, countries and religions. The cultural differences are based on the individual or shared illness narratives surrounding cultural meanings of illness experience. In countries such as India, Cambodia and Muslim majority countries, they each share alternative epistemologies. These are known as knowledge systems that focus on the connections between mind, body, culture, nature, and society.