All Diseases that Start with I (Rare, Deadly, and Many More!)

Welcome to our comprehensive exploration of diseases starting with the letter “I”. In this blog, we delve into a wide array of illnesses affecting various parts of the body and beings – from blood, bone, and eye disorders, to mental, lung, and skin conditions.

We also cover diseases in dogs and cats, as well as those classified as rare, deadly, autoimmune, and bacterial infections. Join us as we unveil the complexities of these conditions and provide insightful information on each.

Top 20 Diseases that Start with I

Below are the top 20 diseases starting with the letter I.

  • Influenza: Common viral respiratory infection
  • Iritis: Inflammation of the iris in the eye
  • Iron-deficiency Anemia: Low iron causes blood deficiency
  • Ichthyosis: Rare, severe skin scaling disorder
  • Interstitial Lung Disease: Scarring of lung tissues
  • Impetigo: Contagious bacterial skin infection
  • Idiopathic Thrombocytopenic Purpura: Low platelet count
  • Insomnia: Chronic sleep disorder
  • Ischemic Heart Disease: Reduced heart blood supply
  • Ileitis: Inflammation of the ileum in intestines
  • IgA Nephropathy: Kidney disease from IgA deposits
  • Inguinal Hernia: Abdominal tissue bulging in the groin
  • Idiopathic Pulmonary Fibrosis: Progressive lung scarring
  • Infective Endocarditis: Heart infection from bacteria
  • Irritable Bowel Syndrome: Chronic gastrointestinal disorder
  • Intracranial Hypertension: Increased brain pressure
  • Ischemic Stroke: Brain blood flow obstruction
  • Idiopathic Hypersomnia: Excessive daytime sleepiness
  • Invasive Ductal Carcinoma: Common breast cancer type
  • Interstitial Cystitis: Chronic bladder pain syndrome


Medical Terms That Start With I

Fitness Words That Start With I

Rare Diseases That Start With I

  • Ivemark Syndrome
  • I-cell disease
  • Idiopathic Aplastic Anemia
  • IPEX Syndrome
  • Idiopathic Juxtafoveal Retinal Telangiectasis
  • Isovaleric Acidemia
  • Infantile Neuroaxonal Dystrophy
  • Immunodeficiency-centromeric instability-facial anomalies syndrome
  • Idiopathic Basal Ganglia Calcification
  • Incontinentia Pigmenti
  • Isolated Congenital Asplenia
  • Idiopathic CD4+ Lymphocytopenia
  • Infantile Refsum Disease
  • Idiopathic Pulmonary Hemosiderosis
  • Inclusion Body Myositis

Deadly Diseases That Start With I

  • Influenza (Flu)
  • Ischemic Heart Disease
  • Infectious Mononucleosis (Mono)
  • Interstitial Lung Disease (ILD)
  • Inflammatory Bowel Disease (IBD)
  • Idiopathic Pulmonary Fibrosis (IPF)
  • Intracranial Hemorrhage
  • Intestinal Obstruction
  • Impetigo
  • Iron-deficiency Anemia
  • Insulinoma (a rare pancreatic tumor)
  • Idiopathic Thrombocytopenic Purpura (ITP)
  • Ileus (intestinal obstruction)
  • Invasive Candidiasis
  • Infantile Botulism

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Other Diseases Beginning With I (Divided By Type)

Autoimmune Diseases That Start With I

  • Idiopathic Thrombocytopenic Purpura
  • Insulin-Dependent Diabetes Mellitus
  • IgG4-related Disease
  • Inflammatory Bowel Disease
  • Immune Thrombocytopenia
  • Idiopathic Pulmonary Fibrosis
  • Inclusion Body Myositis
  • Idiopathic Addison’s Disease
  • IgA Nephropathy
  • Idiopathic Juvenile Arthritis

Blood Diseases That Start With I

  • Iron-deficiency Anemia
  • Idiopathic Thrombocytopenic Purpura
  • Immunodeficiency Syndromes
  • Idiopathic Aplastic Anemia
  • IgA Vasculitis

Bone Diseases That Start With I

  • Idiopathic Osteoporosis
  • Infantile Cortical Hyperostosis
  • Idiopathic Hypercalcemia
  • Idiopathic Juvenile Osteoporosis
  • Intramedullary Osteosclerosis

Eye Diseases That Start With I

  • Iritis
  • Iridocyclitis
  • Idiopathic Intracranial Hypertension
  • Infantile Glaucoma
  • Iridoschisis

Ear Diseases That Start With I

  • Idiopathic Sudden Sensorineural Hearing Loss
  • Inner Ear Malformation
  • Infectious Myringitis
  • Immune-mediated Inner Ear Disease
  • Idiopathic Endolymphatic Hydrops

Hand Diseases That Start With I

  • Idiopathic Carpal Tunnel Syndrome
  • Inclusion Body Myositis (affecting hands)
  • Ichthyosis (hand involvement)
  • Infectious Flexor Tenosynovitis
  • Infantile Digital Fibromatosis

Lung Diseases That Start With I

  • Idiopathic Pulmonary Fibrosis
  • Interstitial Lung Disease
  • Influenza (severe cases)
  • Infectious Bronchiolitis
  • Idiopathic Pleuroparenchymal Fibroelastosis

Liver Diseases That Start With I

  • Infectious Hepatitis
  • Idiopathic Autoimmune Hepatitis
  • Iron Overload Disorders
  • Ischemic Hepatitis
  • Indian Childhood Cirrhosis

Heart Diseases That Start With I

  • Ischemic Heart Disease
  • Infective Endocarditis
  • Idiopathic Hypertrophic Cardiomyopathy
  • Inflammatory Cardiomyopathy
  • Intracardiac Thrombus

Skin Diseases That Start With I

  • Ichthyosis
  • Impetigo
  • Inflammatory Acne
  • Idiopathic Guttate Hypomelanosis
  • Infantile Hemangioma

Bacterial Infection That Start With I

  • Infectious Endocarditis
  • Impetigo
  • Invasive Streptococcal Infection
  • Invasive Meningococcal Disease
  • Infectious Arthritis

As we delve deeper into the realm of diseases, our next sections focus on our furry companions. Discover the various ailments that can affect dogs and cats, beginning with the letter ‘I’. Stay informed and be a better guardian for your beloved pets.

Dog Diseases That Start With I

  • Infectious Canine Hepatitis
  • Inflammatory Bowel Disease
  • Intervertebral Disc Disease
  • Idiopathic Epilepsy
  • Immune-mediated Hemolytic Anemia

Cat Diseases That Start With I

  • Infectious Peritonitis
  • Immunodeficiency Virus
  • Idiopathic Cystitis
  • Inflammatory Bowel Disease
  • Intestinal Lymphoma

diseases that start with i