Hallucinations are the perception of something that doesn’t exist. They can be auditory (heard), visual (seen), tactile (felt) or olfactory (smelled).

These hallucinations can have many causes. The most common causes are recreational drugs and dementia or delirium. But they can also be caused by high fevers or certain illnesses. Some people who have survived serious, life-threatening illnesses, like septic shock, report having very vivid hallucinations while they were in the intensive care unit (ICU).

Hallucinations are often very disturbing and the memories can last, but scientists don’t understand them. A few researchers are looking at how often hallucinations occur among critically ill patients. One study looked at 289 critically ill patients who had been in an ICU for 24 hours or longer and been sedated and intubated (placed on a ventilator). The researchers found that 9.3% of the patient had nightmares and 6.6% said that they had experienced hallucinations. For some people, the hallucinations continue, even after they are no longer in the ICU environment. Another study found that after leaving the critical care area, some patients experienced, “amnesia, continued hallucinations or flashbacks, anxiety, depression, and dreams and nightmares.”

No clear cause for hallucinations

There are theories as to why patients may experience hallucinations, but there are no clear explanations yet. Patients in an ICU are not only fighting a very serious illness, they don’t get a lot of rest. Nursing care is necessary and frequent, and lights are on in the hallways. Even with dimmed lights, patients might not be able to sleep. There is a lot of noise that comes from nurses moving about and talking, machines operating, and alarms beeping. The constant stimulation often causes sleep deprivation. Serious lack of sleep can cause psychological distress.

If you experienced hallucinations while hospitalized for sepsis or septic shock, you are not alone. Some of the people who have shared their stories in our Faces of Sepsis section mention that they saw or heard things that they knew weren’t there.

Getting help

If you are having a hard time dealing with the after effects of sepsis, which can include bad dreams, hallucinations, even memories of the hallucinations, this could be part of post-traumatic stress disorder, or PTSD. There are counselors and therapists who specialize in treating PTSD. They may use a variety of methods, including cognitive therapy, tapping techniques, or eye movement desensitization reprocessing (EMDR). Counseling can be an important component of full recovery from sepsis.


Hallucinations are also a change in mental status. This could be a sign of sepsis.

If you suspect sepsis, call 9-1-1 or go to a hospital and tell your medical professional, “I AM CONCERNED ABOUT SEPSIS.” 

what is sepsis

Would you like to share your story about sepsis or read about others who have had sepsis? Please visit Faces of Sepsis, where you will find hundreds of stories from survivors and tributes to those who died from sepsis.


Updated November 1, 2021.

Read Personal Stories of Sepsis and Hallucinations

Doug Peters


In 2018 started to experience swollen foot, dizziness and hallucinations. Went to a number of specialists, including labs and imaging. My foot hurt the most and all Doctors said it was diabetes and to keep it raised. (Sepsis and Hallucinations) Several blamed it on drinking which I do admit was issue, however I was not and still not diabetic. Finally one day in Nov could not get out of bed for appointment. Grown daughter was at home checking up on me and Mother. She called a visiting nurse and they did come that day. Within minutes of checking my vitals ... Read Full Story

Submit Your StoryView More Stories

Daniel Hernandez

Survivor, Survivor

It was in 2013, early October when I went to our office blood drive. I am an avid donor because I am O+, but my blood donation was rejected. I was surprised as I donated many gallons before. It was found that my iron level was extremely low and they suggested I see my personal physician ASAP. I had noticed some episodes of extreme fatigue. Blood tests at my doctor’s office confirmed my extremely low iron levels and my doctor said it appeared I was bleeding internally. He scheduled a colonoscopy and endoscopy within the next couple of days because ... Read Full Story

Submit Your StoryView More Stories

Mickey Totten

Survivor, Survivor, Survivor

I went to the hospital Sept 3rd 2019 with some chest and shoulder pain. I remember them wanting to do a test for meningitis. That’s the last thing I remember! As I later found out I had walking pneumonia. (Sepsis and Pneumonia) I was intubated but aspirated “food in my lung” and they think that’s where the sepsis started but I still don’t really know. At least that’s what I was told. I woke up in the ICU 17 days later with my leg swollen and red, as well as my hand, twice the normal size from 6 blown IVs ... Read Full Story

Submit Your StoryView More Stories

Sherry Parsons

Survivor, Survivor, Survivor, Survivor

In October 2008 I started getting chills and body aches, I thought it was just a typical flu bug, boy was i wrong. 3 days after feeling ill I started hallucinating, and within a couple hours I couldn’t walk anymore, so my husband rushed me to the emergency. 2 hours after arriving I lost consciousness. When I came to I was told I was put on a ventilator for 2 weeks as i had double pneumonia and sepsis. (Sepsis and Pneumonia) they had to do fluid resuscitation and my blood oxygen level was 38. I wasn’t supposed to live but ... Read Full Story

Submit Your StoryView More Stories

Libby Anderson

Survivor, Survivor, Survivor, Survivor, Survivor

It all began in June of 2017. My wife and I had planned a long weekend away at Fort Bragg with our dog Dexter. At the time we were both ICU RNs working 12-hour night shifts at a hospital near our home. We had finished a grueling 3 shifts in a row. I had a cold. I was tired and coughing a lot. On June 9th, I was excited to leave town and have a relaxing few days off, and so was Mary. When we got to the beach, I was exhausted. Mary took Dexter to the beach, and I ... Read Full Story

Submit Your StoryView More Stories


Hallucinations are the perception of something that doesn’t exist. They can be auditory (heard), visual (seen), tactile (felt) or olfactory (smelled).