The Financial Ombudsman Service (FOS) has reported a more "entrenched" attitude by both consumers and businesses across the board in health insurance complaints.
It has said complaints are being pursued more vigorously than in less economically difficult times.
But it added there had been a notable improvement in recent years in the way insurers handled complaints involving health insurance products.
It said: "The increase in complaints about health insurance is not down to any one issue.
"The majority of complaints we see relate to claims - though provider failure to communicate effectively during what can be a very traumatising period for a consumer can often lead to a wider dispute."
FOS quarterly complaints data showed 291 complaints this year between April and June; critical illness saw 234.
The number of complaints in the same period last year were 179 and 162 respectively. And whole-of-life policy complaints have risen from 393 to 530.
But for IP only 31% of claims were resolved in favour of the consumer, 20% for CI and 26% for whole-of-life.
John Bridge, director of sales and marketing at income protection specialist provider Cirencester Friendly, said the data was not specific to product type but rather a change in consumer attitude towards complaining.
He said: "The rise might reflect people's propensity to complain given the well-publicised PPI problems. If problems are being sent to the ombudsman it means the provider has turned them down already.
"The rise in Income Protection complaints does not reflect what we have seen. I do not think IP in itself is problematic but more that there has been confusion between that and PPI."
Building society Hinckley and Rugby recently reported a significant amount of complaints about PPI from consumers who did not actually have a policy in place.
Only one out of 33 in the last three months made it to the ombudsman, and none were upheld.
Between years 2010/2011 to 2011/2012 FOS complaint satistics showed; an increase of 238 complaints for income protection; 289 for critical illness; and 384 for whole-of-life policies.
