My Mother Is 51 Years Old And I Applied For

My mother is 51 years old and I applied for a Health policy for her. As part of the initial check up she had to undergo TMT along with other mandatory tests. After the check up, the insurer called me up saying that the TMT result is mildly positive and I should go for a plan with higher premium. He sent me a bunch of TMT graphs. I just want to understand how to read those graphs and make a meaningful conclusion and analyse if it is within limits or exceeding.