Imagine visiting one doctor after another because something does not feel right. Tests are done. Medicines are prescribed. Some symptoms improve, while others remain unexplained. Months�or sometimes years�can pass before someone finally puts a name to the condition.
For many people living with a rare disease, this can be their reality.
A rare disease diagnosis can be difficult because these conditions are uncommon individually, may affect different parts of the body, and can sometimes look like more common illnesses. In India, the National Policy for Rare Diseases recognizes lack of awareness, limited diagnostic facilities and the complexity and cost of advanced testing as important challenges in reaching an early diagnosis.
This prolonged search for an answer is often called a �diagnostic odyssey.�
But why does it happen?
What makes a rare disease �rare�?
There is no single definition of a rare disease used worldwide. Definitions and thresholds vary between countries.
Importantly, �rare� does not mean that no one else has the condition. There are thousands of rare diseases. The U.S. National Institutes of Health (NIH) notes that around 7,000 rare and neglected diseases have been identified for which the molecular cause is known, while other sources estimate that the total number of rare diseases is even higher as scientific understanding continues to develop.
Each individual condition may affect relatively few people. However, taken together, rare diseases affect millions of people and families worldwide.
And because each condition is uncommon, recognizing one can be challenging.
1. The symptoms may look like common illnesses
One of the biggest challenges in rare disease diagnosis is that the early symptoms are not always unique.
Fatigue, weakness, pain, developmental difficulties, seizures, digestive problems, breathing difficulties or problems with movement can occur in many different conditions.
A doctor naturally considers common explanations first. This is an important part of medical practice. But sometimes the symptoms persist, appear in unusual combinations, or do not respond as expected to treatment.
That is when a rare disease may need to be considered.
Research on rare disease diagnosis highlights that patients may have heterogeneous clinical presentations�meaning the same disease can look different from one person to another.
This makes the diagnostic process more complicated than simply matching one symptom to one disease.
2. One disease can affect several parts of the body
Some rare diseases are multisystem disorders, meaning they can affect more than one organ or body system.
For example, a person might have a combination of neurological, muscle, heart, eye or developmental problems. Each symptom may initially be assessed separately by a different specialist.
The difficulty is that the connection between these symptoms may not be immediately obvious.
A detailed medical history and a careful review of the patient's overall health can therefore be extremely important. In suspected genetic conditions, a comprehensive assessment may include physical examination, family history and appropriate clinical or laboratory testing.
Sometimes, the key is not one individual symptom�but the pattern created by several symptoms together.
3. Many healthcare professionals may never encounter a particular rare disease
A doctor may see thousands of patients during their career but encounter only a small number of people with a specific rare condition�or possibly none.
This does not mean that doctors are not capable of diagnosing rare diseases. Rather, rarity itself creates a difficult problem: a condition that is rarely seen is naturally harder to recognize.
The Government of India's National Policy for Rare Diseases specifically identifies lack of awareness among primary care physicians and the medical community as one of the challenges affecting early diagnosis.
Increasing awareness among healthcare professionals is therefore an important part of improving the diagnostic journey.
4. There may not be a simple test for every rare disease
For some diseases, diagnosis can be supported by a relatively straightforward laboratory or imaging test.
For others, reaching a diagnosis may require several investigations.
In suspected genetic disorders, doctors may consider different types of genetic testing depending on the clinical situation. These can include testing for specific genes, groups of genes, chromosomal changes or broader approaches such as whole-exome sequencing.
Genetic testing has transformed the diagnosis of many rare conditions, but it is not a single �test for rare diseases.�
A genetic test must be selected and interpreted in the appropriate clinical context. A negative result does not necessarily mean that a genetic condition has been completely ruled out, and some findings may require additional evaluation.
This is why specialist assessment and, where appropriate, genetic counselling can be important parts of the diagnostic process.
5. Misdiagnosis can add another layer to the journey
When a rare disease resembles a more common condition, a patient may initially receive another diagnosis.
This can be especially frustrating for patients and families who continue to experience symptoms despite treatment.
A recent EURORDIS Rare Barometer survey reported that the average time from symptom onset to confirmed diagnosis among surveyed rare disease patients was 4.7 years, and 25% reported having eight or more consultations with healthcare professionals before receiving a diagnosis.
These figures do not mean every patient will experience the same delay. The diagnostic journey varies greatly depending on the disease, symptoms, healthcare system, access to specialists and availability of appropriate testing.
But they demonstrate how complex the journey can become.
6. A family may not have a history of the disease
Many people assume that if no one else in the family has the condition, it cannot be genetic.
That is not always true.
Genetic conditions can occur through different inheritance patterns, and some can arise from a new genetic change that was not previously present in the family. Some genetic diseases may also remain unrecognized in previous generations.
This is why family history is useful�but the absence of a known family history does not automatically exclude a genetic condition.
What can help shorten the diagnostic journey?
There is no single solution, but several steps can make a difference.
Recognizing unusual patterns
Persistent, unexplained or unusual combinations of symptoms deserve appropriate medical evaluation. Certain features�such as unexplained developmental problems, multiple congenital abnormalities, unusual neurological findings or a concerning family history�may prompt consideration of a genetic or rare condition.
Keeping a complete medical history
Patients and caregivers can help by maintaining records of previous diagnoses, investigations, treatments, hospitalizations and relevant family medical history.
A clear timeline of symptoms can also help doctors understand how the condition has changed over time.
Seeking specialist evaluation when appropriate
When a condition remains unexplained, a referral to an appropriate specialist or rare disease/genetics centre may help bring together information from different areas of medicine.
India's National Policy for Rare Diseases identifies improved awareness, diagnostic capabilities and access to appropriate expertise as important areas for addressing rare disease diagnosis.
Using advances in genetic and genomic medicine
Technologies such as next-generation sequencing have expanded the ability to investigate genetic causes of complex and previously undiagnosed conditions. However, these tests are most useful when combined with clinical evaluation and appropriate interpretation.
A diagnosis is more than a name
For a patient and family, receiving a diagnosis can be an important turning point.
A confirmed diagnosis may help explain years of unexplained symptoms, guide appropriate medical care, inform discussions about future health needs and, for some genetic conditions, help families understand whether other relatives may be at risk.
But the journey should not end with the diagnosis.
People living with rare diseases may also need access to appropriate specialists, treatment or supportive care, genetic counselling where relevant, reliable information and emotional and social support.
Most importantly, patients should not feel that their experiences are being dismissed simply because their condition is uncommon.
What can patients and families remember?
If symptoms remain unexplained, it is reasonable to keep asking questions and discussing concerns with a qualified healthcare professional.
You can consider:
Keeping copies of important medical reports and test results.
Maintaining a timeline of symptoms and major health events.
Recording relevant family medical history.
Asking your doctor what possibilities are being considered.
Asking whether specialist referral or further evaluation may be appropriate.
Discussing the purpose, benefits and limitations of any genetic test before undergoing testing.
Seeking information from reliable medical and patient-support organizations rather than relying only on social media or unverified online claims.
A rare disease may be difficult to diagnose�but difficulty in diagnosis should not mean a lack of hope.
Medical knowledge, genetic testing, digital health tools, specialist networks and research are continuing to improve our ability to recognize rare conditions.
At Healing Wings Foundation, we believe that awareness is an important part of this journey. The more people understand about rare diseases, the easier it becomes to recognize that an unexplained health problem may require a different path to diagnosis and care.
Because every patient deserves to be heard. And every unexplained condition deserves to be taken seriously.
Medical Disclaimer
This article is intended for general educational and awareness purposes only. It does not provide medical advice, diagnosis or treatment recommendations and should not be used as a substitute for consultation with a qualified healthcare professional.
Symptoms mentioned in this article can occur in many different medical conditions and do not by themselves indicate a rare disease. If you or someone in your family has persistent or unexplained symptoms, please consult an appropriately qualified healthcare professional. Genetic testing should be undertaken only after appropriate medical evaluation and with professional guidance regarding its potential benefits, limitations and implications.
Information about rare diseases and their diagnosis continues to evolve. Healing Wings Foundation makes reasonable efforts to present information from reliable sources, but readers should consult their healthcare professional for advice specific to their individual circumstances.
