To expand the scope coverage of your health insurance, opt for a critical illness rider at a lower cost. Critical illness policies can be bought as an add-on cover with a basic health insurance policy or as a separate standalone policy.

For instance, a 30-year-old person will have to pay Rs 14,242 to buy a regular health insurance policy from HDFC Ergo General Insurance and Rs 11,288 to buy it from Bharti Axa General Insurance. This policy will cover him up to Rs 10 lakh against normal illnesses as well as critical illnesses. However, in order to save costs, the person can buy a basic health insurance policy with coverage of Rs 5 lakh to take care of normal ailments as well as critical illnesses and an additional Rs 5 lakh coverage specifically for critical ailments. This way the policyholder will have to pay a significantly lower premium of Rs 8,500 (Rs 7,121 for the basic health policy and Rs 1,379 for a critical illness policy) to get the policies from HDFC Ergo and Rs 7,288 (Rs 5,644 for the basic health policy and Rs 1,644 for critical illness policy) for Bharti Axa policies.

"Generally, critical illnesses are covered under plain-vanilla health insurance policies as well. However, since critical illnesses treatments are expensive and hampers the earning capability of the policyholder, an add-on cover is recommended to the customer," said Arun Mehrotra, head of retail underwriting and product development at Iffco-Tokio General Insurance.

Critical illness riders are generally fixed benefit covers, wherein if diagnosed for the ailments mentioned in the policy document, the company pays a fixed sum to the policyholder. Some common illnesses, which are covered under such policies, include cancer, kidney failure, heart attack, liver disease, major burns, coma, major organ transplant, paralysis and multiple sclerosis (damage to brain and nervous system).

However, these policies do not include serious medical conditions such as Alzheimer's disease, HIV/AIDS and Parkinson's disease. Also, the policyholder should go through the fineprint of the policy documents since some early symptoms or precautionary treatments related to critical illnesses might not be covered. Coronary bypass surgery, angioplasty and key-hole surgery are generally excluded. Similarly, initial stages of prostate cancer and paralysis due to Guillain-Barré syndrome from which the patient may recover completely with proper medical attention, might not be covered. The insurers are generally hesitant to provide coverage to defence personnel in active duty or people who are regularly participate in dangerous activities like mountain climbing, scuba diving or racing.

There is a waiting period for such covers. Coverage under a critical illness policy typically starts after 90 days of policy issuance, while it is 30 days in case of normal health insurance policies. Also, claims are rejected if the insurer finds out that the policyholder was already suffering from the ailment before taking the policy.

Under critical illness policies, the sum insured is only paid to policyholder in case he survives for more than 30 days after the diagnosis of the illness. Most Insurers pay a lumpsum of the sum insured at first diagnosis of the disease irrespective of actual hospital and treatment expenses, except a few insurers like Iffco- Tokio General Insurance, which processes cashless claims or reimburses the hospital bills and treatment charges up to the sum insured as in the case of any basic medical policy.

While Bajaj Allianz General Insurance provides maximum coverage of up to Rs 50 lakh, National Insurance provides maximum coverage of Rs 25 lakh. Similarly, Rs 20 lakh is the maximum coverage from Reliance General Insurance and Future Generali India Insurance. ICICI Lombard General Insurance and Bharti Axa General Insurance cover up to Rs 6 lakh and 5 lakh, respectively. HDFC Ergo General Insurance, Star Health and Allied Insurance and Apollo Munich Health Insurance provide coverage of up to Rs 10 lakh.

"In case a policyholder is diagnosed with a critical illness, he should inform his insurer at the earliest, so that the claim process can be completed quickly. After the claim is settled and payment is made, the policyholder may utilise the amount for his treatment as well as for any other purposes," said Karan Chopra, head of retail business, HDFC Ergo General Insurance.

Submitting treatment documents is mandatory to make a claim. Maintaining old medical reports is also advisable since the insurer might ask for these documents while processing the claim. To make sure the claim is legitimate and control insurance frauds, insurers may also ask the policyholder to visit their empanelled doctors.

"The Insurance Regulatory and Development Authority (Irda) is planning to standardise definitions of critical illnesses and their coverage, so that it becomes easier for the policyholders to compare products. Incorporating new illnesses is a continuous process and in order to cover a few additional diseases, premium might go up by 15-20 per cent," said Subrahmanyam B, head of health vertical at Bharti AXA General Insurance.