Difficult-to-diagnose diseases

Disease Directory

Some of these diseases are rare. Others are common but easily missed, because their symptoms mirror something more familiar. Either way, patients often wait years for a diagnosis that names what is happening to them.

Volv Global works across a growing number of these conditions. Each disease page sets out the numbers behind it, the signs and symptoms most often missed, and what our research is learning about the gap to diagnosis.

Diseases 02

Explore the disease directory areas

Acute Respiratory Distress Syndrome

A life-threatening lung condition that goes unrecognised in as many as 4 in 10 patients on the day it first appears.

Alpha-1 Antitrypsin Deficiency

A hereditary condition strongly linked to COPD and liver disease, with most people who carry it never diagnosed.

Breast Cancer

Breast cancer is a group of cancers defined by receptor status, and that status now determines more than 90% of treatment choice. Most patients are found through screening, so the opportunity lies in finding patients whose subtype, biomarker or germline testing has not kept pace with new treatment options, such as HER2-low disease, post-CDK4/6 inhibitor mutations and BRCA carriers.

Fabry Disease

A rare, inherited condition that often goes unrecognised for over a decade, as symptoms mimic more common diseases.

Friedreich Ataxia

Friedreich ataxia is a difficult-to-diagnose inherited mitochondrial disease causing progressive ataxia, cardiomyopathy and scoliosis, with symptoms split across specialities that delay a single-gene diagnosis.

Huntington Disease

Huntington disease is a fatal inherited brain disorder causing movement, cognitive and psychiatric decline; most gene-positive carriers remain undiagnosed for years before any clinical sign appears.

Multiple System Atrophy (MSA)

MSA is a fatal, rapidly progressive neurodegenerative disease combining severe autonomic failure with parkinsonism or ataxia, difficult to diagnose because it mimics Parkinson’s disease.

Neuroendocrine Tumours

A group of slow-growing but serious tumours whose vague, wide-ranging symptoms often delay diagnosis by years.

Pompe Disease

A rare muscle-wasting condition whose milder, later-onset form can take five to twelve years to diagnose.

Sjögren's Disease

Sjögren's Disease is a chronic autoimmune disease causing dry eyes and mouth, with sicca symptoms scattered across ophthalmology, dentistry and rheumatology so the underlying systemic cause often goes unrecognised.

Spinal Muscular Atrophy

Spinal muscular atrophy destroys motor neurones from birth. Three therapies now exist, yet UK adults wait 25 years between diagnosis and treatment.

Thymidine Kinase 2 Deficiency (TK2D)

TK2D is an ultra-rare, progressive mitochondrial muscle disease causing DNA depletion and respiratory failure; patients are difficult to diagnose and often go unrecognised until crisis.

Transthyretin Cardiac Amyloidosis

ATTR-CM is a progressive infiltrative heart disease caused by misfolded transthyretin protein, routinely mistaken for common heart failure with preserved ejection fraction and left undiagnosed for years.

WHIM Syndrome

WHIM syndrome is an ultra-rare inherited immune disorder causing neutropenia, warts and recurrent infections, split across four specialties so it is difficult to diagnose and often missed for years.

X-Linked Hypophosphataemia

XLH is a hereditary phosphate-wasting disorder causing rickets in children and osteomalacia in adults; most adults were never genetically confirmed and remain difficult to find in claims data.

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