–Claire, living with AHP

About AHP

AHP is a rare genetic disease

Acute hepatic porphyria (AHP), a subset of porphyria, refers to a family of rare genetic diseases characterized by potentially life-threatening attacks and, for some people, chronic debilitating symptoms that negatively impact daily functioning and quality of life. There are four types of AHP:

The different types of AHP

Most common
  • Acute intermittent porphyria (AIP)
  • Variegate porphyria (VP)
  • Hereditary coproporphyria (HCP)
  • ALAD-deficiency porphyria (ADP)

Extremely rare

The symptoms of AHP often resemble those of other diseases in the gastrointestinal, gynecological, and neurological or neuropsychiatric areas. Severe symptoms can lead to hospitalizations and unnecessary procedures. Misdiagnosis is common, and people with AHP can wait years for a confirmed diagnosis.

Find out more about how AHP works by watching the video below. It takes you inside the body, for a deeper understanding of the disease, its signs and symptoms, and common misdiagnoses.

What AHP Does To The Body

  • In people with a genetic defect for AHP, one of the enzymes in the heme pathway doesn’t work properly
  • Heme is essential to our body and is necessary for our liver to function properly
  • In the liver, the heme pathway is controlled by an enzyme called ALAS1
  • When ALAS1 activity is increased, the enzyme that doesn’t work properly is unable to keep up. This results in the buildup of neurotoxic intermediates called aminolevulinic acid (ALA) and porphobilinogen (PBG) in the liver which are released throughout the body.
  • ALA and PBG are harmful to nerve cells and have been associated with the symptoms and attacks of AHP
  • Sudden attacks are associated with widespread dysfunction within the nervous system and a wide array of symptoms which can mimic those of other diseases, making a diagnosis difficult

AHP can affect anyone

  • Although AHP affects people of all races, it is most common in Caucasians
  • AHP affects people of both sexes and can occur at any age, but most cases are in women between the ages of 15 and 45
  • Approximately 83% of people with AHP are women, while around 17% are men
  • Not everyone who has a genetic mutation for AHP will develop symptoms

Everyone experiences AHP
in a different way

Acute attacks can be life-threatening and can last for days. Not everyone who has AHP experiences acute, sudden attacks. In some people they happen rarely—in others more often. Some people experience daily symptoms from their AHP, even when they are not having an attack. This is part of what makes diagnosis difficult.

ACUTE AHP attacks

Person experiencing severe, unexplained abdominal pain during an acute hepatic porphyria attack

Acute attacks can cause severe problems in many parts of the body and often require hospitalization.


Person experiencing ongoing pain from acute hepatic porphyria

Chronic symptoms, such as anxiety, nausea, pain, and muscle weakness can take a serious toll on some people with AHP.

There are simple tests your doctor can perform to confirm if you have AHP

Person diagnosed with acute hepatic porphyria

Recognizing the signs and symptoms

Because the symptoms of AHP can mimic many other diseases, being aware of its many possible symptoms can help your doctor identify the disease as early as possible. Recognizing the symptoms is a crucial first step to understanding the disease and knowing how to reduce the likelihood of attacks.

Severe, unexplained abdominal pain of varying intensity without fever or a high white blood cell count is the most common symptom, occurring in more than 90% of people diagnosed with AHP. People with AHP are likely to also experience at least one of many other, seemingly unrelated symptoms.

Signs and Symptoms of AHP

Person with acute hepatic porphyria symptoms

Central Nervous System

  • Confusion
  • Anxiety
  • Seizures
  • Insomnia
  • Hallucinations
  • Depression

Peripheral Nervous System

  • Limb weakness or pain
  • Numbness
  • Fatigue
  • Tiredness
  • Paralysis
  • Respiratory paralysis
  • Sensory loss


  • Rapid heart rate
  • High blood pressure

Cutaneous (Skin) Symptoms*

  • Leisons or blisters on sun-exposed skin


  • Constipation or diarrhea

Autonomic Nervous System

  • Unexplained abdominal pain
  • Pain in back or chest
  • Nausea and vomiting


  • Dark or reddish urine
  • Low blood sodium

The symptoms of AHP can vary from person to person and change over time. Not every person with AHP will experience all the symptoms listed here and some people will have symptoms more frequently or more severe than others.

*Hereditary coproporphyria and variegate porphyria only.

There are a number of triggers for AHP attacks

Common triggers are shown below. Since triggers can be different for every person, there may be others not listed here.

Medications as a trigger


Hormones as triggers

Hormones including levels of estrogen and progesterone. These hormones fluctuate the most during the 2 weeks before a woman’s menstruation begins.

Alcohol consumption as a trigger


Smoking as a trigger


Stress induced triggers

caused by:

Fasting as a trigger

Fasting or low-carb diets

AHP can be misdiagnosed as other conditions

The signs and symptoms of AHP can be mistaken for those of other conditions, shown below. These misdiagnoses can lead to unnecessary treatments, surgeries, and hospital stays.

Gastrointestinal misdiagnoses

Gastrointestinal disorders

  • Irritable bowel syndrome (IBS)
  • Acute gastroenteritis with vomiting
  • Hepatitis
  • Crohn’s disease
Neurological or neuropsychiatric misdiagnoses

Neurological/neuropsychiatric disorders

  • Fibromyalgia
  • Guillain-Barré syndrome
  • Psychosis
Gynecological misdiagnoses

Gynecological disorders

  • Endometriosis
Abdominal conditions as misdiagnoses

Abdominal conditions requiring surgery

  • Appendicitis
  • Cholecystitis
  • Peritonitis
  • Intestinal occlusion

Learn How Doctors Diagnose AHP