Trypanophobia Definition

Trypanophobia can be defined as an intense, life-consuming fear of injections or hypodermic needles that are used in various medical procedures. Although it is quite normal for most people to experience a certain extent of fear or discomfort related to such procedures, a trypanophobic individual fears them to such an extent that it leads him or her to avoid medical treatment completely, or display other forms of anxious or avoidant behavior.

Sometimes, people having this disorder tend to faint when they are exposed to injections or needles, even when they are not themselves involved in that particular medical procedure.

The condition is sometimes referred to by various other names, such as:

  • Belonephobia
  • Enetophobia
  • Aichmophobia

However, these terms might also point to a rather general fear of various sharply pointed objects.

Trypanophobia Incidence

It is believed that at least around 10% of the adult population in America is afraid of needles. The actual number of people having this phobia is likely to be larger as most of the severe cases are not documented as these sufferers tend to avoid all forms of medical intervention.

Trypanophobia Causes

A number of factors can contribute to the gradual development of this specific type of phobia. The factors may vary for each patient. In most instances, however, some forms of traumatic experiences are believed to be responsible for the development of this fear. These may include witnessing some painful medical procedure either firsthand or secondhand, an apprehension of being controlled or restrained due to a repressive upbringing, or improper handling of needles and injection-related medical procedures during the past. Trypanophobia may also occur due to physical hypersensitivity.

It is also possible for a needle phobic patient to experience the symptoms of a phobic attack by only witnessing medical procedures that involve needles even without being injected. A sight of an injection may make a sufferer experience vasovagal syncope; collapsing or fainting is also quite common. Although the exact cause of this is unknown, it might be because the phobic imagines himself or herself undergoing that procedure. Recent neuroscience research has shown that feeling a pinprick sensation and watching the hand of another person getting pricked by pin activates the same portion of the brain.

Trypanophobia and Evolution

Dr. James G. Hamilton, who has published the pioneering paper focusing on needle phobia, has suggested that the genetic form of needle phobia is rooted in evolution. Thousands of years ago, the human beings who painstakingly avoided stab wounds or other occasions of pierced flesh had a greater potential for survival.

The discussion on the role of evolution in needle phobia in the article written by Dr. Hamilton focuses on the vasovagal form of needle phobia, a subtype of the blood-injection-injury phobia. It is characterized by a 2 phase vasovagal response. Initially, a brief acceleration of the blood pressure and heart rate can be noticed. This is then followed by a quick dropdown of blood pressure and heart rate, which sometimes leads to unconsciousness. This loss of consciousness is occasionally accompanied by convulsions as well as numerous quick changes in the levels of various hormones.

Some of the other medical articles have discussed the additional aspects of possible connections that vasovagal syncope has with evolutionary fitness observed in blood-injection-injury phobias.

A particular evolutionary psychology theory explains that some types of fainting or loss of consciousness are non-verbal signs which developed as a response to an increased inter-group hostility during the Paleolithic age. A non-combatant person who has fainted indicates that he or she does not pose as a threat. This explains the association between loss of consciousness and stimuli like injuries and bloodletting as well as nature of the gender differences.

Trypanophobia Types

A fear of needles may appear in several forms, which are discussed below:


Even though most forms of specific phobias originate from the psyche of the affected individuals themselves, the vasovagal reflex reaction, which is the most common form of needle phobia seen in almost 50% of all trypanophobic patients, is an inherited condition. Nearly 80% of people having a fear of needles have reported about a first degree relative with the same disorder. Individuals having vasovagal needle phobia are usually afraid of the thought, sight or even the feeling of needles and needle-like objects. The main sign of vasovagal fear is the vasovagal syncope, i.e., fainting caused by reduced blood pressure.

Several people who faint during various needle procedures report of having no conscious fear of a needle procedure itself. However, they may have a major fear of a vasovagal syncope reaction. A particular study published in the medical journal called Circulation revealed that in many individuals having this condition, an initial occurrence of a vasovagal syncope episode during some needle procedure might be the main cause of the phobia rather than a basic fear of sharp objects or needles.


Associative trypanophobia is the 2nd most common form of needle phobia affecting almost 30% of all patients. It is the classic form of specific phobia wherein some personally experienced traumatic incident such as a very painful medical procedure or witnessing a friend or a family member undergo something similar leads a patient to associate every needle involving procedure with the original experience.


Resistive trypanophobia occurs when an underlying fear incorporates not only an apprehension of injections or needles, but also of being restrained or controlled. It generally stems from a repressive upbringing or improper handling of some prior needle procedures, such as by forced emotional or physical restraint. This type of needle phobia can be seen in around 20% of all affected patients.


Hyperalgesic trypanophobia is another type of phobia that does not necessarily have much to do with the fear of an actual needle. Individuals having this form actually suffer from inherited hyperalgesia or hypersensitivity to pain. The pain associated with injections seems so great to these people that many cannot understand how anyone can undergo such procedures. The hyperalgesic form makes up 10% of all needle-phobes.

Trypanophobia Symptoms

The various signs and symptoms experienced by a patient of Trypanophobia may depend on the type of the condition that he or she is having. Although there are certain common features that occur in almost all the various types, certain specific symptoms are attributed to each form of fear of needles. The common symptoms of Trypanophobia, based on the various types, are discussed below:

Vasovagal fear of needles

The physiological characteristics associated with the vasovagal form of needle phobia include:

  • Pallor
  • Nausea
  • Tinnitus
  • Sweating
  • Feeling faint
  • Panic attacks
  • Initial higher heart rate and blood pressure which is followed by a sharp drop in both while having the injection

Associative fear of needles

This type of the disorder gives rise to symptoms which are mainly psychological in nature, such as:

  • Insomnia
  • Panic attacks
  • Extreme unexplained anxiety
  • Preoccupation with a forthcoming procedure

Resistive fear of needles

The common symptoms of resistive fear of needles include:

  • Flight
  • Avoidance
  • Combativeness
  • Violent resistance
  • High heart rate along with very high blood pressure

Hyperalgesic fear of needles

The signs and symptoms of this form of fear include:

  • Trembling
  • Rapid heartbeat
  • Extreme avoidance
  • Shortness of breath
  • Feelings of panic or dread
  • Extreme explained anxiety
  • Uncontrollable or automatic reactions
  • Raised heart rate and blood pressure immediately before the needle penetration or some seconds before

Trypanophobia Comorbidity

Fear of needles is frequently comorbid with certain other phobias and/or psychological problems at more critical levels. Iatrophobia, i.e., an extreme irrational fear of doctors can often be seen in patients having a needle phobia.

Trypanophobia Triggers

A needle-phobic individual does not need to be physically present in a doctor’s chamber to experience anxiety or panic attacks. There are numerous triggers in outside world every day that might lead to an attack through an association. Some of these stimuli include:

  • Blood
  • Nurses
  • Injuries
  • Doctors
  • Dentists
  • Hospitals
  • Paper pins
  • Hospital gowns
  • White lab coats
  • Examination rooms
  • Reading literature about the fear
  • The sight of a needle physically or even on the TV screen
  • The antiseptic smell that is associated with hospitals and medical offices
  • The sight of an individual who is physically similar to the patient’s general health care provider

Trypanophobia Treatment

Numerous methods of treatment for needle phobia have been mentioned in medical literature. Although they have been effective in managing specific instances of this condition, very little guidance is available that can help to predict which mode of treatment might be effective for a particular case. The most common ways of treating this phobia, the effectiveness of which has been proven in certain specific cases, are mentioned below:

Ethyl Chloride Spray or other freezing agents

Although these sprays are easily administered, they provide only a superficial management of pain.


Iontophoresis involves driving an anesthetic medication through the skin with the help of an electric current. Although it provides substantial anesthesia, it is generally unavailable for customers on commercial market and certain medical experts consider it to be inconvenient for usage.

Jet Injectors

Jet injectors function by introducing substances to the body by a jet of high-pressure gas instead of a needle. Although this procedure eliminates the needle, many people have reported that they do cause more pain and discomfort. Apart from this, these injectors are also helpful in only a certain number of situations that involve needles, such as insulin and inoculations.


EMLA is a type of topical anesthetic cream made out of a eutectic combination of prilocaine and lidocaine. It is sold as a prescription cream in United States, and can also be obtained without prescription in certain other countries. Although EMLA is not as effective as the procedure of iontophoresis since it does not go as deep as the iontophoresis-driven anesthetics, the EMLA cream is much simpler to apply than iontophoresis. The cream penetrates deeper than most ordinary topical anesthetics, thereby working efficiently for many individuals.


Ametop gel often gives better results than EMLA cream for eradicating pain during venepuncture.

Nitrous Oxide or laughing gas

This can provide sedation and help in reducing anxiety for a patient, apart from providing mild analgesic effects.

Lidocaine/tetracaine patch

This is a self-healing patch that contains a eutectic combination of tetracaine and lidocaine. It has been made available in numerous countries, and has also been approved specifically by government agencies to be used in needle procedures. It is sold as Synera in United States and as Rapydan in the European Union. The patch is packaged within an air-tight pouch. The patch starts to heat up to some extent when it is removed from packaging and exposed to air. It takes around 20-30 minutes for the patch to achieve the full anesthetic effect.

Cognitive behavioral therapy

The effectiveness of cognitive behavioral therapy may vary greatly, depending on the particular patient as well as severity of the phobia. There is some speculation regarding the effectiveness of such behavioral treatments for curing specific phobias like the blood/injection/injury type phobias, although some available data seem to suggest efficiency of approaches such as exposure therapy. Any treatment method that endorses relaxation might be contraindicated for treating trypanophobia as this approach promotes a reduction in blood pressure that helps to only enhance the vasovagal reflex. As a result of this, the graded exposure approaches might include a coping method that relies on applied tension to prevent the complications associated with vasovagal response to a specific blood/injury/injection type stimulus.

Inhalation General Anesthesia

This can eliminate all pain as well as all memory associated with any needle procedure. It is generally regarded as an extreme solution that is not covered by medical insurance in majority of cases. Most physicians also refrain from ordering it. The procedure can be expensive and risky and might require a stay at the hospital.


Dr. James Hamilton suggests that Benzodiazepine medications such as lorazepam or diazepam (Valium) might help to reduce the anxiety experienced by needle phobics. They start acting within 5-15 minutes from the time of ingestion. Sometimes, a relatively larger oral dose might be necessary.

Other methods of treatment include:

  • Hypnosis
  • Psychotherapy
  • Applied tension therapy
  • Systematic desensitization

Trypanophobia Prognosis

Although most phobias can pose as a serious threat to the life of affected individuals, a needle phobia is among the rare few that can even kill the patients. In severe cases, the dropping of blood pressure that is caused by vasovagal shock reflex might lead to death.

Although the phobia generally responds positively to treatment methods such as cognitive behavioral therapy, it might take a long time for the results to be apparent. The time taken by a particular patient to overcome his or her fear can vary greatly, depending on the severity of the condition as well as receptivity to treatment.

Famous people with Trypanophobia

Many celebrities have a fear of needles or needle-like sharp objects. Some of these include:

  • Kimbo Slice
  • Jackie Chan
  • Gerard Way
  • Snoop Dogg
  • Alice Cooper
  • Derrick Rose
  • Sonny Liston
  • Conan O’Brien

One Response

  1. Gravityfalls September 28, 2015

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