Iliohypogastric nerve

Last revised by Henry Knipe on 19 Mar 2024

The iliohypogastric nerve arises from the anterior ramus of the L1 nerve root of the lumbar plexus along with the ilioinguinal nerve. It is a sensory nerve that provides lateral and anterior cutaneous branches supplying the posterolateral gluteal skin and skin in the pubic region.

Gross anatomy


The iliohypogastric nerve arises with the ilioinguinal nerve as a single trunk from the anterior ramus of the L1 nerve root of the lumbar plexus. This trunk enters the abdomen behind the medial arcuate ligament and runs anterolaterally parallel and superior to the iliac crests traversing the anterior surface of the quadratus lumborum muscle. The common trunk is short and the nerve soon divides in to iliohypogastric and ilioinguinal nerves at the lateral edge of the psoas muscle.

Course and branches

The iliohypogastric nerve emerges at the lateral edge of the upper part of the psoas muscle, coursing obliquely inferiorly to reach the iliac crest, anterior to the quadratus lumborum muscle and posterior to the kidney.

As it reaches superior to the iliac crest posteriorly, it pierces the transversus abdominis muscle to course in between the transversus abdominis and internal oblique muscles.

Immediately above the iliac crest, it gives off a lateral cutaneous branch which pierces the internal and external oblique muscles to supply the posterolateral gluteal skin.

The remaining part of the iliohypogastric nerve (anterior cutaneous branch) continues coursing anteriorly to reach just above and medial to the anterior superior iliac spine before piercing the internal oblique muscle. From there, it courses obliquely to reach just superior to the superficial inguinal ring, piercing the aponeurosis of the external oblique muscle to become cutaneous and supplying the surrounding skin.


The iliohypogastric nerve gives off anterior and lateral cutaneous branches and supplies branches to the abdominal musculature along its course.

The lateral cutaneous branch arises from the iliohypogastric nerve above the iliac crest and supplies the upper part of the buttock behind the area supplied by the subcostal nerve.

The anterior cutaneous branch is the continuation of the iliohypogastric nerve anteriorly. Approximately 2.5 cm above the superficial inguinal ring the nerve terminates by supplying the skin over the lower part of the rectus abdominis and mons pubis.


Proximally the iliohypogastric nerve lies on the anterior surface of the quadratus lumborum muscle and posterior to the kidney. The ilioinguinal nerve travels inferiorly to the iliohypogastric nerve and has a more oblique course as it travels to the iliac crest typically traversing the iliacus muscle.

Variant anatomy

The iliohypogastric nerve has been shown to be absent in ~20% of lumbar plexi examined in cadaveric studies. Occasionally, the iliohypogastric and ilioinguinal nerves remained conjoined (within a common epineurium) well after exiting the substance of the psoas major musculature although this variation was quite rare. 

The size of the iliohypogastric nerve is inversely proportional to the size of the ilioinguinal nerve.


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