Health is good. Intelligence is sometimes associated with health. Wikipedia has two articles on the relationship between intelligence and health. The other is here. So wouldn't you want to know more about your intelligence?

Clarity's index of sometimes subtle neurological conditions that impair cognitive functionl

Kleine–Levin syndrome

a rare sleep disorder characterized by persistent episodic hypersomnia and cognitive or mood changes. Many patients also experience hyperphagia, hypersexuality and other symptoms.

KLS can be diagnosed when there is confusion, apathy, or derealization in addition to frequent bouts of extreme tiredness and prolonged sleep*

Vascular dementia

Patients suffering from vascular dementia present with cognitive impairment, acutely or subacutely as in mild cognitive impairment, after one or many cerebrovascular events. The symptoms of dementia may progress gradually or step-wise after each small stroke. Some people may appear to improve between events and decline after more silent strokes

Patients develop progressive cognitive, motor and behavioural signs and symptoms. A significant proportion also develop affective symptoms. These changes typically occur over a period of 5–10 years. If the frontal lobes are affected, which is often the case, patients may present as apathetic or abulic. This is often accompanied by problems with attention, orientation...

Binswanger's disease

This disease is characterized by loss of memory and intellectual function and by changes in mood. These changes encompass what are known as executive functions of the brain. It usually presents between 54 and 66 years of age, and the first symptoms are usually mental deterioration or stroke

Cortical dementia is atrophy of the cortex which affects ‘higher’ functions such as memory, language, and semantic knowledge whereas subcortical dementia affects mental manipulation, forgetfulness, and personality/emotional changes. Binswanger’s Disease has shown correlations with impairment in executive functions, but have normal episodic or declarative memory. Executive functions are brain processes that are responsible for planning, cognitive flexibility, abstract thinking, rule acquisition, initiating appropriate actions and inhibiting inappropriate actions, and selecting relevant sensory information. There have been many studies done comparing the mental deterioration of Binswanger patients and Alzheimer patients. It has been found in the Graphical Sequence Test that Binswanger patients have hyperkinetic perseveration errors which cause the patients to repeat motion even when not asked whereas Alzheimer patients have semantic preservation because when asked to write a word they will instead draw the object of the word.

Autism

• Different working memories

• includes Asperger syndrome:

Although individuals with Asperger syndrome acquire language skills without significant general delay and their speech typically lacks significant abnormalities, language acquisition and use is often atypical. Abnormalities include verbosity, abrupt transitions, literal interpretations and miscomprehension of nuance, use of metaphor meaningful only to the speaker, auditory perception deficits, unusually pedantic, formal or idiosyncratic speech, and oddities in loudness, pitch, intonation, prosody, and rhythm.[1] Echolalia has also been observed in individuals with AS. Pursuit of specific and narrow areas of interest is one of the most striking possible features of AS. Three aspects of communication patterns are of clinical interest: poor prosody, tangential and circumstantial speech, and marked verbosity. According to the Adult Asperger Assessment (AAA) diagnostic test, a lack of interest in fiction and a positive preference towards non-fiction is common among adults with AS. peech may convey a sense of incoherence; the conversational style often includes monologues about topics that bore the listener, fails to provide context for comments, or fails to suppress internal thoughts. Individuals with AS may fail to detect whether the listener is interested or engaged in the conversation. The speaker's conclusion or point may never be made, and attempts by the listener to elaborate on the speech's content or logic, or to shift to related topics, are often unsuccessful. It maps well to general-processing theories such as weak central coherence theory, which hypothesizes that a limited ability to see the big picture underlies the central disturbance in ASD. Asperger called the condition "autistic psychopathy" and described it as primarily marked by social isolation

More on Central Coherence Theory here

Meningitis

In children there are several potential disabilities which may result from damage to the nervous system, including sensorineural hearing loss, epilepsy, learning and behavioral difficulties, as well as decreased intelligence. These occur in about 15% of survivors. Some of the hearing loss may be reversible. In adults, 66% of all cases emerge without disability. The main problems are deafness (in 14%) and cognitive impairment (in 10%).

The most common symptoms of meningitis are headache and neck stiffness associated with fever, confusion or altered consciousness, vomiting, and an inability to tolerate light (photophobia) or loud noises (phonophobia).

Meningitis can lead to serious long-term consequences such as deafness, epilepsy, hydrocephalus and cognitive deficits, especially if not treated quickly.[

Toxic encephalopathy

Consequence:

. Toxic encephalopathy has a wide variety of symptoms, which can include memory loss, small personality changes/increased irritability, insidious onset of concentration difficulties, involuntary movements, fatigue, seizures, arm strength problems, and depression

Accessibility:

In addition, chemicals, such as lead, that could instigate toxic encephalopathy are sometimes found in everyday products such as cleaning products, building materials, pesticides, air fresheners, and even perfumes. These harmful chemicals can be inhaled (in the case of air fresheners) or applied (in the case of perfumes)

Recovery:

Long term studies have demonstrated residual cognitive impairment (primarily attention and information-processing impairment resulting in dysfunction in working memory) up to 10 years following cessation of exposure