Since the mind loves metaphors, it is easy for it to create a darkness or cloudiness in the body. The placement of the dark spots is an indication of when or where the issue takes place, and once you learn to read it, half the diagnostic work is done for you.
Head — negative thoughts, often from childhood, mental or emotional abuse. Throat — they don't speak up, or are afraid to share their true thoughts. Heart — a broken heart, grief they are still hurting from. Abdomen / womb — an unborn child (aborted or miscarried), a childless person, or negative energy from being raped. Feet — often turns into chains, common in clients who say they feel stuck; usually stems from a past lifetime when they were trapped, chained, or imprisoned.
Possible reasons for the darkness — negative energy, fear or pain left over from a hurtful or tragic event: from this life or childhood, rape or molestation, physical abuse, mental and emotional abuse, limiting beliefs, sadness, stuck energy, "not good enough," fears, the womb, a past life, unexplainable pain, a soul or entity, a spell or curse, an unborn child.
Negative energy trauma in this life. Often, people have traumatic experiences that create negative energy which they hold onto — an accident, emotional or verbal abuse, being fired; too many events to list. Each one needs to be handled with a lot of compassion.
The client is best served when they can see the event take place once again, and can then interrupt the event by changing the outcome (the mind doesn't know the difference) or telling off the other person. This technique allows the client to have their voice heard. Whether it is to a parent or a boss, the feeling of being free to confront the person and really say what is on their mind is a beautiful thing.
Once they have finished saying their piece, you may want the other person to explain themselves, or have them say they are sorry. Then it is important to cut the cords — to the person and also to the situation. Cutting the cords actually cuts the potency of the negative emotion. Now when the client thinks of the situation, they don't have the negative emotional surge they used to have.
Practice
Take the placement list and add one client scenario you can imagine for each area (head, throat, heart, womb, feet). This is how you'll start recognizing patterns the moment a client names a location.