This means:
“There may be early symptoms or changes that could indicate dementia, and you should pay attention to them rather than ignoring them. The post says to look at the first comment for more information.”
Breakdown
“Early signs of dementia” = changes in memory, thinking, behavior, communication, or ability to manage everyday activities that may occur in the early stages of dementia.
“You should NEVER ignore” = a dramatic way of saying these changes should be taken seriously.
“Check 1st comment” = “Look at the first comment below the post,” where the creator presumably provides the signs or additional information.
“NEVER” in capital letters = emphasizes urgency and is typical of attention-grabbing social-media headlines.
Tone
This is a dramatic health/social-media headline designed to create concern and encourage people to read the comments.
Importantly, having one of these symptoms does not automatically mean someone has dementia. Many changes in memory or thinking can have other causes, and a healthcare professional can help determine what is actually happening.
