Risk Factors for Idiopathic Intracranial Hypertension
The primary risk factors for IIH are female sex (particularly reproductive age), obesity (BMI >30 kg/m²), and recent weight gain of 5-15%, with these three factors defining the typical IIH patient profile. 1, 2
Demographic Risk Factors
- Female sex of childbearing age is the strongest demographic predictor, with 70.9% of adult IIH cases occurring in women 3
- Obesity (BMI >30 kg/m²) is present in the vast majority of typical IIH cases 1, 2
- Recent weight gain of 5-15% in the year preceding diagnosis is a critical precipitating factor 1, 4
- Pre-menopausal status increases risk in women 4
Modifiable Risk Factors
- Weight gain is the most important modifiable risk factor, with 5-15% weight gain preceding diagnosis 1, 4
- Obesity itself drives the metabolic underpinnings of cerebrospinal fluid dysregulation 4, 5
- The condition is increasingly recognized as a systemic metabolic disease rather than purely neurological 4
Medical Comorbidities
- Anemia is among the most frequent comorbidities associated with secondary intracranial hypertension 3
- Renal diseases are commonly associated with increased intracranial pressure 3
- Hypertension is a frequent comorbidity in IIH patients 3
Medication-Induced Risk Factors
The following medications are strongly associated with drug-induced intracranial hypertension (DIIH):
- Vitamin A derivatives (Category IV-V association) 6
- Tetracycline-class antibiotics (Category IV-V association) 6
- Recombinant growth hormone (Category IV-V association) 6
- Lithium (Category IV-V association) 6
- Corticosteroids (Category III - moderate association) 6
Weakly associated medications include cyclosporine, progestin-only contraceptives, combined oral contraceptives, fluoroquinolones, and others 6
Hormonal and Endocrine Factors
- Pregnancy or hormonal changes may contribute to disease onset or recurrence 7
- Emerging evidence suggests neuroendocrine effects on the mineralocorticoid receptor may explain increased cerebrospinal fluid production 5
- The reproductive age window in women suggests hormonal influence on disease pathophysiology 2, 4
Important Clinical Caveats
- Even patients with typical IIH phenotype (obese women of reproductive age) should be screened for secondary causes, as 40.4% of secondary intracranial hypertension cases also present with obesity 3
- Weight regain after initial loss is a major risk factor for disease recurrence throughout life 7
- The global increasing incidence of obesity is driving a parallel increase in IIH incidence 8
- Among pediatric cases, 13.4% are obese or overweight, indicating obesity is relevant across age groups 3