Bleeding blood

Platelet Deficiency:

Can't form Temporary hemostatic plug

Signs and symptoms:

Bleeding Time prolonged

Bleeding from small vessels and superficial scratches won't stop

Petechiae

Ecchymosis / purpura (bigger petechiae)

Epistaxis = nosebleeds (most common sign of platelet disorder)

Coagulation Deficiency:

Can form the temporary hemostatic plug just fine = Bleeding time is normal

Can't convert the fibrinogen in the temporary plug to fibrin, so all they have is the temporary unstable plug which can be dislodged very easily

Signs and Symptoms: (normal bleeding time)

Late re-bleeding (bleeding stops with temp. plug but later plug is dislodged and bleeding starts again)

Menorrhagia 

Hemarthrosis = bleeding into joints / closed spaces

GI bleeds