Old Mutual Wealth has expanded its critical illness (CI) plan ‘Protect' to 65 conditions and cover for all types of heart attack, vascular disease and extended cover for strokes.
The enhancements will be available to new customers and to existing policyholders that bought Critical Illness cover since April 2013. Previously the plan covered 56 illnesses.
Additional conditions covered include sickness or injury that results in at least 10 days in a UK intensive care unit on a mechanical ventilator and Kennedy's disease.
Old Mutual Wealth is also paying the full sum assured for all types of heart attack.
Coverage has also been extended to cover both spinal stroke and eye stroke and to include strokes either with or without permanent symptoms.
Improvements to existing definitions mean a range of other conditions will also benefit from increased cover.
Old Mutual Wealth also said it is also making significant improvements to surgery benefit.
Customers will now receive the cover payment in full as soon as they are placed on an NHS waiting list. This means the it will provide up-front surgery benefits without the need for a quote from a private hospital.
The range of surgeries covered will also expand from 4 to 11, to include brain tumour and major organ transplants.
Ian Jefferies head of protection at Old Mutual Wealth said:"Our aim in making these substantial enhancements has been to offer the most comprehensive Critical Illness cover that is available in the market.
We have also condensed, simplified and clarified a number of existing conditions in order to make the product easier for customers to understand. Overall these changes will enable us to pay more claims to customers at the most crucial times."
Old Mutual Wealth was previously Skandia, which rebranded earlier this year.