Although your hairstylist is a significant part of your hair journey, you have to make sure you are doing your part as well.
Things that can affect the health of your hair: Hormonal Shifts - "Hormone levels can affect the quality and the quantity of hair". Read Anna Jimenez write up on this very subject. Stress - Stress can cause Anxiety and Sever Anxiety can tell the body to stop producing more hairs. Take the Calm Clinic's anxiety tes tto see if you are in this group. Lack of Protein ( Food) - Some people who go on crash diets that exclude protein or who have abnormal eating habits may develop protein malnutrition. Medications and Supplements - There are an alarming amount of medications and supplements that list hair loss as a side effect. Make sure you are checking with your doctor and the medications manufacturer for common side effects. Thyroid Gland Malfunction and Other Disorders - Hair growth DEPENDS on the proper function of the thyroid gland. If the thyroid gland is not functioning properly and you are not taking steps to correct if ( surgery, medication) there won't be much your hairstylist can do to maintain strength. I suffer from Graves Disease and know myself if I do not take my medication not only will it have me fatigued it will also have my hair feeling like the end of a broom.
Make your stylist well aware of special circumstances that may affect your health that is beyond their control to create a plan to battle these forces. :)