Patients with hypergraphia exhibit a wide variety of writing styles and content. While some write in a coherent, logical manner, others write in a more jumbled style (sometimes in a specific pattern). In some cases hypergraphia can manifest with compulsive drawing. Drawings by patients with hypergraphia exhibit repetition and a high level of detail, sometimes mixing both compulsive writing and drawing together.

Hypergraphia is a symptom of temporal lobe epilepsy, a condition of reoccurring seizures caused by excessive neuronal activity, but it is not a common symptom among patients. Less than 10 percent of patients with temporal lobe epilepsy exhibit characteristics of hypergraphia. Temporal lobe epilepsy patients may exhibit irritability, discomfort, or an increasing feeling of dread if their writing activity is disrupted. To elicit such responses when interrupting their writing suggests that hypergraphia is a compulsive condition, resulting in an obsessive motivation to write. A temporal lobe epilepsy may influence frontotemporal connections in such a way that the drive to write is increased in the frontal lobe, beginning with the prefrontal and premotor cortex planning out what to write, and then leading to the motor cortex (located next to the central fissure) executing the physical movement of writing.

Most temporal lobe epilepsy patients who suffer from hypergraphia can write words, but not all may have the capacity to write complete sentences that have meaning.

Hypergraphia is the tendency for extensive and compulsive writing or drawing, and has been observed in persons with temporal lobe epilepsy who have experienced multiple seizures. Those with hypergraphia display extreme attention to detail in their writing. Some such patients keep diaries recording meticulous details about their everyday lives. In certain cases, these writings demonstrate extreme interest in religious topics. Also, these individuals tend to have poor penmanship. The novelist Fyodor Dostoyevsky showed symptoms of Geschwind syndrome, including hypergraphia. In some cases hypergraphia can manifest with compulsive drawing. Drawings by patients with hypergraphia exhibit repetition and a high level of detail, sometimes morphing writing with drawing

Some individuals may exhibit hyperreligiosity, characterized by increased, usually intense, religious feelings and philosophical interests, and partial (temporal lobe) epilepsy patients with frequent numinous-like auras have greater ictal and interictal spirituality. Some auras include ecstatic experiences. It has been reported that many religious leaders exhibit this form of epilepsy. These religious feelings can motivate beliefs within any religion, including Voodoo, Christianity, Islam, and others. Furthermore, in Geschwind syndrome, "in someone from a strongly religious background hyperreligiosity might appear as deeply felt atheism". There are reports of patients converting between religions. A few patients internalize their religious feelings: when asked if they are religious they say they are not. One reviewer concluded that the evidence for a link between temporal lobe epilepsy and hyperreligiosity "isn't terribly compelling".

Focal impaired awareness seizures are seizures which impair consciousness to some extent: they alter the person's ability to interact normally with their environment. They usually begin with a focal aware seizure, then spread to a larger portion of the temporal lobe, resulting in impaired consciousness. They may include autonomic and psychic features present in focal aware seizures.

Signs may include:

- Motionless staring

- Automatic movements of the hands or mouth

- Confusion and disorientation

- Altered ability to respond to others, unusual speech

- Transient aphasia (losing ability to speak, read, or comprehend spoken word)

These seizures tend to have a warning or aura before they occur, and when they occur they generally tend to last only 1–2 minutes. It is not uncommon for an individual to be tired or confused for up to 15 minutes after a seizure has occurred, although postictal confusion can last for hours or even days. Though they may not seem harmful, due to the fact that the individual does not normally seize, they can be extremely harmful if the individual is left alone around dangerous objects. For example, if a person with complex partial seizures is driving alone, this can cause them to run into the ditch, or worse, cause an accident involving multiple people. With this type, some people do not even realize they are having a seizure and most of the time their memory from right before or after the seizure is wiped. First-aid is only required if there has been an injury or if this is the first time a person has had a seizure.

Other medical conditions with similar symptoms include panic attacks, psychosis spectrum disorders, tardive dyskinesia, and occipital lobe epilepsy.

Graphomania (from Greek "γραφειν" — writing, and μανία — insanity), also known as scribomania, refers to an obsessive impulse to write. When used in a specific psychiatric context, it labels a morbid mental condition which results in writing rambling and confused statements, often degenerating into a meaningless succession of words or even nonsense and called then graphorrhea (cf. hypergraphia). The term 'graphomania' was used in the early 19th century by Esquirol and later by Eugen Bleuler, becoming more or less common. Graphomania is near condition to typomania - obsessiveness with seeing one's name in publication or with writing for being published, excessive symbolism or typology.

Outside the psychiatric definitions of graphomania and related conditions, the word is used more broadly to label the urge and need to write excessively, professionally or not. Max Nordau, in his attack of what he saw as degenerate art, frequently used the term 'graphomania' to label the production of the artists he condemned (most notably Richard Wagner or the French symbolist poets )

Milan Kundera ironically explains proliferation of non-professional writing as follows: