Health and Disease

Anosognosia – Not Knowing What You Don’t Know

This article discusses the causes, consequences, and significance of anosognosia, a mental condition that may be easily overlooked without caution. The strange concept of this condition raises the question of how one chooses to believe in something, and whether the act of believing is localized in the brain.

By Melle Hsing

Published 3:12 PM EST, Sat April 3, 2021


Patients may respond differently to news about their health — with sadness, shock, anger, relief, and more. In some cases, patients do not know how to respond, not because of denial but the lack of self-awareness in noticing  a problem. This condition is called anosognosia, which refers to the failure of an individual to recognise that they have a disorder or mental illness. Someone not knowing that they have anosognosia is in and of itself anosognosia. They may say phrases such as “there’s nothing wrong with me!” or “I don’t need your help”. With a lack of insight, a patient may refuse to get a proper medical check-up or receive crucial treatment for their illness. This article raises awareness of anosognosia as a real mental condition and  the causes and consequences of it. Undoubtedly, anosognosia also highlights the importance of a doctor’s insight.

Causes and Consequences

How does anosognosia differ from when the patient doesn’t know about the existence of their disease simply because the symptoms are hard to observe in real life? Well, patients with this condition may still believe that nothing is wrong with them even when there is strong evidence of a diagnosis, stemming from the  structural changes in their brain. The presentation of a medical condition differs from person to person, and hence the symptoms of anosognosia can manifest in various ways depending on the individual. Some may feel anger when others tell them that something they disagree with, while others may shrug off opinions. There are also those who acknowledge that they have a disease or illness one day, and refuse to believe they have it in the next. Being able to differentiate between ignorance and real disbelief is one of the challenging parts of diagnosing anosognosia.

Not all researchers agree with each other when talking about the influence of demographics on the occurrence of anosognosia. Since patients lack awareness of their illness, this means that anosognosia can only be present by definition in those with health problems, in particular, mental illnesses. Is there a biological link between a particular mental illness and anosognosia? 

According to the National Alliance on Mental Illness, 60% of schizophrenic patients do not believe that they have schizophrenia. There have also been cases where patients with bipolar disorder, Huntington’s, Alzheimer’s, Parkinson’s, and traumatic brain injury lack insight to their health issues. Studies involving patients with schizophrenia have given researchers insight to the possible biological causes of anosognosia in the brain. Self-awareness is localised in many parts of the brain in a broad network, particularly anatomical structures in the frontal lobes and parietal lobes, hence anosognosia may arise from deficient activation in these areas.

Serious Mental Illness and Anosognosia - Treatment Advocacy Center

Figure 1: Differences in brain activation between patients with low insight and high insight. Sourced from the Treatment Advocacy Center (Brain scans).

Anosognosia is the main reason why patients with schizophrenia and bipolar disorder refuse treatment. Hence, support from family members, friends, and healthcare professionals is very important to the benefit of the patient’s health.

The Doctor’s Insight

As Oliver Sacks once said, “it is singularly difficult, for even the most sensitive observer, to picture the inner state, the ‘situation’ of such patients, for this is almost unimaginably remote from anything he himself has ever known.” Empathy plays an integral role in doctor-patient communication because patients with anosognosia may feel genuinely confused, misunderstood, and even discriminated against due to the conflicting views about their own health. Hence, doctors need to think about how a patient feels, and take the patient’s opinions into serious consideration. The doctor’s response to information disclosed by a patient could influence the patient’s perception about the doctor, the doctor-patient relationship, and their trust in the healthcare team.

Patient autonomy is an extremely important aspect of professional medical practice, whereby doctors should respect the patient’s rights and decisions about their own care and treatment. When deciding on a treatment plan for any disease, doctors need to assess the mental capacity of a patient beforehand to see whether they are suitable for making such decisions. Assessing mental capacity is all the more important for patients with anosognosia. As discussed previously, patients with anosognosia may refuse any treatment or care because they believe that nothing is wrong with them, when in reality something is definitely wrong. Even if a doctor deems the patient’s decision to be unwise, he or she must still respect the decision made. Dealing with anosognosia is tricky. 

To resolve this problem, doctors usually engage the patient in self-evaluation about their own health using interviews or questionnaires to assess the presence of anosognosia. This process may be more complicated when anosognosia is prevalent in certain impairments such as motor impairment, because of the possibility that the patient has either explicit or implicit anosognosia.


While anosognosia may not seem like an immediate harm to the patient’s health, it can very well mislead doctors, family members, and the patient themselves to different conclusions about the patient’s condition and clinical needs. Therefore, understanding this condition is helpful for avoiding detrimental errors in clinical practice.

Melle Hsing, Youth Medical Journal 2021


“Anosognosia.” American Psychological Association, Accessed 7 Mar. 2021.

“Anosognosia.” National Alliance on Mental Illness, Accessed 7 Mar. 2021.

Brain scans of schizophrenic patients with low insight and high insight. Treatment Advocacy Center, June 2016, Accessed 26 Mar. 2021.

Cocchini, Gianna & Beschin, Nicoletta & Sala, Sergio. (2012). “Assessing Anosognosia: A Critical Review.” Acta Neuropsychologica. doi: 10. 419-443. 10.5604/17307503.1023693. Accessed 28 Mar. 2021.

Jewell, Tim. “What Is Anosognosia?” Healthline, Accessed 16 Mar. 2021.

“Key Issues of Anosognosia.” Treatment of Advocacy Center, Accessed 26 Mar. 2021.

McLean, Brendan. “The Difficulty in Seeing Your Own Illness.” National Alliance on Mental Illness, Accessed 16 Mar. 2021.”What Is Anosognosia?” Treatment Advocacy Center, Accessed 16 Mar. 2021.


By Melle Hsing

Melle Hsing is a student at Chinese International School in Hong Kong. She is interested in the fields of medicine, biology, and neuroscience.

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