Mayo Clinic Report

Dyslexia symptoms can be difficult to recognize before your child enters school, but some early clues may indicate a problem. Once your child reaches school age, your child's teacher may be first to notice a problem. The condition often becomes apparent as a child begins learning to read.

Dyslexia is characterized by a delay in the age at which a child begins to read. Most children are ready to learn reading by kindergarten or first grade, but children with dyslexia often can't grasp the basics of reading by that time. Talk with your doctor if your child's reading level is below what's expected for his or her age or if you notice other signs or symptoms of dyslexia.

When dyslexia goes undiagnosed and untreated, childhood reading difficulties continue into adulthood.

http://www.mayocliniccom/health/dyslexia/DS00224/DSECTION=symptoms