G44.04 Chronic paroxysmal hemicrania

ICD-10-CM Diagnosis Code G44.04: Chronic Paroxysmal Hemicrania

ICD-10-CM code G44.04 represents chronic paroxysmal hemicrania, a primary headache disorder. Clinical literature defines the chronic form as headache attacks occurring for more than one year without remission or with remission periods lasting under one month. It is classified as a trigeminal autonomic cephalalgia and is noted as an indomethacin-responsive headache syndrome. 1 2 3 4

Plain-language overview

Chronic paroxysmal hemicrania is a primary headache disorder that clinical literature categorizes as a relatively rare condition. It is one of four unique headache types classified under the group known as trigeminal autonomic cephalalgias. 1 2

What this code represents

In the ICD-10-CM system, code G44.04 maps to the diagnosis of chronic paroxysmal hemicrania. This code serves to identify the condition within the 2026 version of the diagnostic classification system. 3 4

Clinical context

The chronic form of paroxysmal hemicrania is defined clinically as headache attacks occurring for more than one year without remission or with remission periods lasting less than one month. 1

Clinical literature identifies chronic paroxysmal hemicrania as an indomethacin-responsive headache syndrome. Non-steroidal anti-inflammatory drug alternatives like non-invasive vagus nerve stimulation have been explored for patients who are intolerant to indomethacin. 2

Documentation considerations

Clinical sources define chronic paroxysmal hemicrania by its duration, specifically as attacks occurring for more than one year without remission or with remission periods lasting less than one month. This temporal threshold provides the clinical framework for the diagnosis. 1

What the sources add

The clinical literature from PMC establishes the disease classification and duration criteria for chronic paroxysmal hemicrania, while the coding sources provide the corresponding ICD-10-CM alphanumeric identifier. Together, these sources link the clinical definition to the specific diagnostic code. 1 2 3 4

One clinical source outlines the classification of paroxysmal hemicrania as a trigeminal autonomic cephalalgia, whereas a separate clinical source details the specific temporal threshold that distinguishes the chronic form from the episodic form. 1 2

Sources

1. Headache management: pharmacological approaches — pmc.ncbi.nlm.nih.gov; accessed 2026-07-25.
2. Therapeutic Approaches for the Management of Trigeminal Autonomic Cephalalgias — pmc.ncbi.nlm.nih.gov; accessed 2026-07-25.
3. EVS Explore — evsexplore.semantics.cancer.gov; accessed 2026-07-25.
4. ICD-10 Coding Changes for Primary Care and its Benefits — outsourcestrategies.com; accessed 2026-07-25.